Glossary

Total database output requested:
Total number of records: 725

Item		Description
Abdomen		The posterior (rear) of the three body divisions of an insect. The other two body divisions are head and thorax. In spiders, the abdomen is the posterior of the two major divisions of the body. The other one is the cephalothorax.
Abiotic		Non-living, physical or chemical. For example: abiotic damage to a crop includes damage by solar radiation, temperature, humidity, pH.
Abiotic factors		Abiotic = Inanimate, inorganic, not living. In agriculture, abiotic factors include temperature, moisture, light, etc.
Acari		An order in the class Arachnida, including the mites and ticks. They are characterized by an oval, one-part body and a minute to small body size.
Acaricide		(= Miticide) Pesticide that can kill mites, ticks and spiders.
Acceptable daily intake		(a.d.i.) The daily ingested intake of a pesticide (expressed as mg/kg body weight per day) that, over the entire lifetime of a human being, standard man = 60 Kg, appears to be without appreciable risk on the basis of all known facts at a specified time.
Acetylcholine		(ACh) Chemical transmitter of nerve and nerve-muscle impulses between nerve and across nerve-muscle junctions. In normal nerve activity it is hydrolysed by the enzyme cholinesterase after each impulse. Some pesticides work by blocking the function of the cholinesterase enzyme.
Activator		A substance added to a pesticide that increases its toxicity resulting in more effective control.
Active ingredient		(a.i.) The toxic component of a formulated pesticide.
Acute		Of short duration, characterised by sharpness or severity. Opposite of chronic.
Acute toxicity		The toxicity of a substance determined at the end of 24 hours. The toxicity that causes damage or death from a single dose or exposure.
Adhesive		(= Sticker) Substance added to a formulation to increase the surface retention (persistence) of a pesticide.
Adjuvant		A substance that improves the properties of a pesticide formulation. For example wetting agents, spreaders, emulsifiers, dispersing agents, foam suppressants, penetrants and correctives.
Adult		The last, or mature, stage in the life cycle of an insect. It is the reproductive stage.
Adulterate		To reduce the purity of a material below the standards it is supposed to represent. For example a pesticide that does not conform to the professed standard or quality as documented on its label or labelling.
Adulticide		Chemical substance that kills the adult stage of arthropod pests (insects, mites).
Aestivation		Dormancy during a warm or dry season which allows insects to survive during periods of extreme heat or drought.
Aflatoxins		Toxins that are produced by the fungus Aspergillus flavus.
Aggregation		Coming together of organisms into a group. For example a swarm of locusts.
Agricultural chemical		Chemicals used to improve agricultural production and to protect crops (pesticides, plant hormones, chemical fertilizers, etc.).
Agricultural commodity		Any plant or part of a plant, animal or animal product that is to be bought or sold.
Agro-ecology		The study of ecology in relation to agricultural systems.
Agro-ecosystem		The ecosystem composed of cultivated land and surrounding or intermixed uncultivated areas, the plants contained or grown thereon, and their associated animals.
Alatae		Winged forms.
Algicide		A chemical substance used to control algae
Alkaline soil		Soil containing alkali salts, usually in amounts that are harmful to crop growth. Usually the pH of these soils is above 8.5.
Allomone		A compound released by one organism which evokes a reaction in an individual of a different species and that is favourable to the emitter but not to the receiver. Examples: 1) Plant allomones which deter feeding. 2) Alarm pheromones in ants.
Amber		Fossilized gum (tree sap). It is a hard, sometimes clear, yellowish-brown material, often containing fossilized insects.
Ametabola		Insects which do not undergo a metamorphosis.
Anatomy		Science which deals with the structure of organisms.
Annual		Plant species that completes its life cycle in one year.
Annulated		With ring-like segments or divisions (usually referring to the antennae).
Anoplura		An insect order, including the sucking lice. They are external parasites that feed by sucking blood. They have a flattened, wingless body, sucking mouthparts, and an incomplete metamorphosis.
Ant		Any of various social insects of the family Formicidae (order Hymenoptera). Only the males and fertile females have wings. They are living in colonies that have a complex social organization.
Antagonism		An ecological association between organisms in which one or more of the participants is harmed or has its activities limited.
Antagonist		An agent or substance that counteracts the action of another.
Antenna		A pair of jointed appendages located on the head of an insect above the mouthparts, which are usually used for smelling and feeling (touching), and in some cases for hearing.
Anterior		Front. In front of.
Anthesis		The period during which the flower is open.
Anthracnose		A plant disease having characteristic lesions, necrosis and hypoplasia on stems, leaves and fruit. Anthracnose is usually caused by certain imperfect fungi e.g. Colletotrichum, Gloeosporium, Kabatiella.
Anti-drift agent		A substance added to pesticides to reduce the number of fine droplets produced at the spray nozzle.
Anti-feedant		A substance that deters or inhibits feeding by an insect but does not necessarily kill it.
Anti-fungal		A chemical substance that kills or inhibits fungi.
Anti-microbial		A chemical substance that kills or inhibits micro-organisms.
Anti-viral		A chemical substance that inhibits or kills viruses.
Antlion		A common name for a larva of the family Myrmeleontidae (order Neuroptera). They dig cone-shaped pitfalls in the sand for trapping ants.
Apex		Top ( plural = Apices ). For example the tip of a root or shoot.
Aphicide		An insecticide especially effective against aphids.
Aphid		Insect belonging to the family Aphididae in the order Hemiptera, suborder Homoptera. Sometimes referred to as "plant louse".
Apical		At the end, tip, or outermost part.
Apices		See Apex.
Apiculture		Bee-keeping. Culture and care of bees.
Apodous larva		Culture and care of bees.
Apterae		Wingless forms.
Apterous		Without wings. Wingless.
Apterygota		Subclass of the insects including the most primitive orders with no metamorphosis. Except for the size, all larval stages closely resemble the adults (which are wingless).
Aquatic		Living in the water. (see also: Terrestrial)
Arachnida		Class within the phylum Arthropoda. It includes a numbers of orders such as Araneae (Spiders) and Acari (Mites and Ticks).
Arachnologist		Person who studies arachnids (spiders, scorpions, ticks, mites, etc.)
Arachnophobia		Fear of spiders.
Araneae		An order belonging to the class Arachnida, comprised of the spiders. They are characterized by two body parts (cephalothorax and abdomen), eight legs, and a pair of fangs (chelicerae).
Araneida		See: Araneae
Araneology		Study of spiders.
Arborial		Living on trees and other large plants.
Arista		A large bristle located on the dorsal side of the last antennal segment in the insect order Diptera.
Arolium		A padlike lobe projection between the tarsal claws of many insects.
Arthropoda		A phylum within the animal kingdom. It includes Crayfish, Millipedes, Centipedes, Spiders, and Insects. Arthropoda have a segmented body with a hard outer skeleton (exoskeleton). Usually the segments are grouped in two or three body regions. The body has a bilateral symmetry and it has paired segmented appendages.
Aspirator		A simple suction device for capturing small insects.
Azadirachtin		Azadirachtin is one of the active ingredients in pesticides that are produced from the neem tree. It acts as a powerful insect antifeedant and growth regulator.
Bacillus		A rod-shaped bacterium.
Bacillus thuringiensis		A spore forming bacterium which can be used to control certain insect pests especially caterpillars.
Bactericide		A substance that is toxic to bacteria.
Bacteriophage		A virus that replicates inside a bacterium.
Bait		A formulation, including attractants, toxicants, and/or mechanical devices used as a lure for killing pests. Usually poisoned foodstuff used to attract and kill insects or rodents.
Basal		At the base. Near the point of attachment. ( = opposite to apical )
Beak		Proboscis. The long, protruding mouthpart structures of an insect with piercing-sucking mouthparts. This type of mouthparts can be found in the suborders Heteroptera (true bugs) and Homoptera (cicadas and others).
Bee		Any of several insects of the superfamily Apoidea (order Hymenoptera). Bees are winged, hairy-bodied, usually stinging insects, including both solitary and social species. They are characterized by sucking and chewing mouthparts for gathering nectar and pollen.
Beetle		Any of numerous insects of the order Coleoptera. Beetles have biting mouthparts. Their forewings are modified to form a strong covering that protects the underlying membranous hind wings when at rest.
Beneficial insects		Insect that serves the interest of man. For example insect pest predators and parasitoids that help to keep pest populations under control. Also bees and other pollinating insects are beneficial insects.
Biocide		A chemical substance that is toxic to a wide range of organisms (e.g. insects, snails, birds, people).
Biodegradable		Capable of being broken down by micro-organisms. It usually refers to biological processes in soil, water and sewage. It can also refer to man-made organic compounds such as pesticides.
Biological control		The use of natural enemies such as predators, parasites, and pathogenic micro-organisms or antagonists to control pest populations, diseases or weeds. This can be achieved either through conservation and stimulation of indigenous natural enemies, or by the importation and mass introduction of exotic natural enemies.
Biological control agent		Any biological agent that adversely affects pests.
Biological pesticide		A pesticide the active ingredient of which consists of a living organism or virus.
Bioluminescence		The ability of certain organisms to produce light. For example in some insects in the orders Collembola, Diptera and Coleoptera.
Biorational pesticides		Pesticides based on bacteria, viruses, fungi or protozoa; includes pest control agents, and chemical analogues of naturally occurring biochemicals (e.g. pheromones, insect growth regulators).
Biotype		A group of genetically almost identical individuals but distinguished by criteria other than those of morphology (e.g. parasitic ability, resistance)
Bird scarer		Device to repel birds from crops (e.g. scarecrow).
Bisexual		Having both sexes present and functional in the same organism.
Blast		Plant disease similar to blight.
Blight		Common name for a number of different diseases on plants. Blight is characterised by the rapid death of plant tissue (e.g. leaf blight, blossom blight, shoot blight).
Bloom period		The period during which flowers are opened.
Blossom stage		Crop stage from the time the first blossoms open until the petals fall.
Blotch		A plant disease characterised by large, necrotic and irregular in shape, spots or blots on leaves, shoots and stems.
Booting stage		Growth stage of grain crops when the leaf sheath swells up due to the growth of developing spike or panicle.
Botanical pesticide		A pesticide obtained from plants, e.g. pyrethrum, nicotine, azadirachtin and rotenone.
Braconid		Insect belonging to the family Braconidae (Hymenoptera). This is a family of parasitoid wasps. Many braconid species are important in biological control of pests.
Brand name		Trade name. Name given to a product sold by a company to distinguish it from similar products made by other companies.
Broad-leaved plants		Plants that are not mosses and not grasses.
Broad-spectrum pesticide		A non-selective pesticide that has activity against a wide range of pests. For example, a broad-spectrum insecticide will kill a wide range of insects.
Broadcast application		Application over an entire area rather than only on rows, beds or middles (also referred to as blanket application). For example broadcast application of a pesticide.
Brood		All of the individual insects that hatch from the eggs laid by one mother.
Brown Plant Hopper		(= BPH) Rice pest in South and South-East Asia.
Bug		True bugs are insects of the suborder Heteroptera (order Hemiptera). They are wingless or four-winged, with mouthparts adapted for piercing and sucking. The term bug is sometimes used to refer to any insect or similar organisms such as centipedes and mites.
Butterfly		Any of various insects of the order Lepidoptera. Butterflies have slender bodies, knobbed antennae, and four broad, usually colorful wings. Most butterflies are day-flying insects. (see also: Moth)
Calibrate		To determine the amount of pesticide that will be applied to the target area.
Calling		A virgin female moth releasing sex pheromones to attract males for mating.
Callus		Tissue overgrowth around a wound or canker.
Calorie		A unit of heat or energy. One calorie is the amount of heat required to raise the temperature of one gram of water by 1 degree Celcius.
Campodeiform		A larva having the form of a bristletail (Thysanura) of the genus Campodea. A campodeiform larva is elongate and flattened, and has well developed legs and antennae. Usually they are active.
Canker		A necrotic, sometimes sunken or cracked area surrounded by living tissue on a stem. Canker is a necrotic symptom of disease in woody plant parts. The necrosis is restricted to an area surrounded by callus.
Cannibalistic		Feeding on other individuals of the same species.
Carbamates		A chemical class of insecticides. Carbamates are derived from carbamic acid and have anti-cholinesterase activity.
Carcinogen		A substance that can causes the initiation of tumor formation (cancer).
Carnivore		Flesh eating. An organism (usually an animal) which feeds on animals (see also herbivore and omnivore).
Carnivorous		Feeding on the flesh of other animals. (see also: Herbivorous).
Carrier		Inert material serving as diluent and vehicle for a chemical compound (active ingredient) to facilitate its application. For example in pesticides that are formulated as a dust. Organism harbouring a parasitic organism without itself showing symptoms of the disease caused by that organism.
Caste		A form or type of adult in a social insect colony. For example the soldiers and workers in a colony of termites.
Caterpillar		Larva of an insect belonging to the order Lepidoptera (butterflies and moths). Caterpillars usually have a cylindrical body, a distinct head capsule, chewing mouthparts, thoracic legs, and abdominal prolegs. The name caterpillar is also used for larvae of scorpionflies and sawflies.
Caudal		Referring to the tail or rear part of the body.
Causal agent of disease		That which is capable of causing disease.
Causal organism		The pathogen that produces a given disease.
Cell		An area in the membrane of an insect wing that is partly (open cell) or completely (closed cell) surrounded by veins.
Cell culture		The growing of cells in vitro.
Cellulose		A carbohydrate composed of repeating units of the sugar glucose. Cellulose is a main component of the cell walls of plants and algae.
Centipede		Animal belonging to the class Chilopoda. Some characteristics of centipedes are an elongate, flattened, wormlike shape, a hard external skeleton, two body sections (head and many-segmented trunk), 15 to 30 pairs of legs (one pair per trunk segment), a pair of antennae with 14 or more segments, and simple eyes.
Cephalothorax		The body region made up of the head and thorax joined together. For example the anterior (front) of the two major divisions of the body of a spider.
Cerambycidae		Family of beetles containing the longhorn beetles or long-horned beetles.
Cerci		Plural of Cercus.
Cercus		One of a pair of feeler-like appendage located near the tip on an insect's abdomen.
Cereal		A grass grown for its edible seed or grain, such as maize, wheat, rice, barley and millet.
Chemical control		Control of pests with synthetic pesticides.
Chemical name		Scientific name of the active ingredient(s) in a formulated pesticide.
Chemoreceptor		Receptor activated by chemicals. In insects, chemoreceptors for smell are usually situated on the antennae. Receptors for taste may be found on all parts of the insect's body, but they are located mainly on mouthparts and their feet (or tarsi). Some insects, including bees and wasps, have taste organs on their antennae.
Chemosterilant		Chemical substance that cause sterilisation.
Chilopoda		A class of arthropods. See: Centipedes.
Chitin		A chemical compound (nitrogenous polysaccharide) occurring in the cuticle of insects and other arthropods.
Chlorophyll		ally active part of most plants.$
Chlorosis		Yellowing or mottling of normally green tissue as a result of lack of chlorophyll, through its failure to develop, or destruction by chemical effects, disease etc.
Cholinesterase		An enzyme that is necessary for proper nerve functioning. Cholinesterase is inhibited or damaged by pesticides belonging to the organophosphates and carbamates.
Cholinesterase inhibitor		A substance which inhibits the enzyme chlorinesterase. It prevents transmission of nerve impulses from one nerve cell to another or to a muscle.
Chronic		Of long duration e.g. 'chronic disease or infection'. Opposite of acute.
Chronic effect		A slow and continuous effect.
Chronic symptoms		Symptoms that appear over a long period of time.
Chronic toxicity		The effect of a chemical following prolonged and repeated exposure.
Chrysalis		The pupa of a butterfly.
Class		An animal classification category. A subdivision of a phylum, consisting of a group of related orders. (See: Classification)
Classification		The animal kingdom is divided in phyla, for example the phylum Arthropoda. Each phylum is subdivided in classes, for example the class Hexapoda (= insects). Classes are subdivided into orders, for example the order Coleoptera (= beetles). Orders are divided into families, families into genera (singular: genus), and genera are divided into species.
Clavate		Clubbed or enlarged at the tip. For example a clavate antenna.
Clay		Type of soil with mineral soil particles that are less than 0.002 mm in diameter.
Climate		The total long-term characteristics of weather for any region It includes rainfall, temperature, humidity, wind direction and wind velocity.
Clone		A population of individuals all derived asexually from the same single parent. For example a group of plants originating by vegetative propagation from a single plant.
Clubbed		With the distal part expanded, enlarged, or swollen. For example a clubbed antenna.
Coccoid		Sphere-shaped.
Coccus		A spherical bacterium.
Cocoon		A silken case in which a pupa is formed.
Coleoptera		Insect order containing the beetles. Beetles are characterized by hard front wings that meet in a straight line in the middle of the back, chewing mouthparts, and a complete metamorphosis.
Collembola		Primitive insect order containing the springtails. They are characterized by wingless bodies with a spring mechanism, chewing mouthparts, and no metamorphosis.
Collophore		A tube-like structure on the ventral side of the first abdominal segment of the body of springtails (order Collembola).
Collophore		A tube-like structure on the ventral side of the first abdominal segment of the body of springtails (order Collembola).
Colony		A group of individuals of the same species of insects, living together, often in a type of a nest.
Combined nitrogen		Nitrogen in a form in which it is bonded to other elements. For example ammonia (NH3), nitrate (NO3-), and nitrite (NO2-).
Common name		The name of an insect that is used only in a particular region or country (see also: Scientific name).
Common pesticide name		A common chemical name given to a pesticide by a recognised committee on pesticide nomenclature. Many pesticides are known by a number of trade or brand names but have only one recognised common name..
Compatible		In chemistry: Two compounds are compatible when they can be mixed without undesirably affecting each other's properties. In biology: Refers to a pathogen being able to form a parasitic relationship with a host plant.
Compensation		The ability of plants or plant parts to make up for damage caused to other parts of the plant. For example a rice plant that lost a tiller because of attack by a stem borer will produce new tillers to compensate for this.
Competition		Competition occurs when two or more organisms, or populations, interfere with or inhibit one another as they strive to secure a resource that is in limited supply. For example weeds compete with crop plants for nutrients, moisture, light and other essential growth factors. Competition can also occur between individuals of the same species.
Complete metamorphosis		A type of development consisting of four distinct stages; egg, larval stages, pupa and adult. A complete metamorphosis is characteristic for insect orders belonging to the endopterygota.
Compost		A mixture of organic materials used to improve soil structure and fertility. Compost is usually prepared by microbial degradation of plant materials.
Compound eye		The major insect eye, which is composed of many individual facets or lenses.
Compound eye		A compound eye includes many lenses, each with six sides. These fit together like the cells of a honeycomb. Some insects can see sharp images and different colors. All insects can see movement better than shape.
Concentrate		Refers to a commercial pesticide preparation before dilution for use.
Concentrate spraying		Direct application of a pesticide concentrate without dilution.
Concentration		The proportion of active ingredient in liquid or dust pesticide preparation, before or after dilution. The concentration can be shown for example as kilo per litre or as a percentage by weight.
Contact herbicide		Herbicide that kills those plant parts with which it comes into contact.
Contact insecticide		Insecticide that kills insects by contact with the cuticle.
Contact pesticide		Pesticide which relies on coming into contact with the target organism. For example a contact insecticide.
Contact poison		Pesticide that kills when it contacts some external part of a pest. For example contact insecticide.
Control		In research experiments: The untreated subjects that are compared with those given crop protection treatment.
Corium		The elongate, usually thickened, basal part of the front wing in members of the suborder Heteroptera (true bugs)
Cornicle		One of a pair of tubular structures extending from the posterior part of the abdomen of aphids (family Aphididae).
Cosmopolitan		Widely distributed over the globe.
Costa		A stout wing vein that usually forms the front edge of the wing.
Cotyledon		Seed leaf. Leaf-like structures in the embryos of seeds. Grasses have one cotyledon in each seed (monocotyledon), while most other plants have two (dicotyledon).
Cotyledon leaves		The first leaf, or pair of leaves developed by the embryo of seed plants.
Cover		Proportion of surface area of plant material on which a pesticide has been deposited.
Cover crop		A crop grown to maintain a plant cover on the land to prevent erosion and leaching. If the cover crop is turned under to improve the soil, it becomes a green-manure crop.
Coxa		The basal segment of the insect leg.
Crawler		The active first instar of a scale insect.
Cremaster		A hook-like spine located on the posterior end of a Lepidoptera pupa. Its function is to attach the pupa to a surface.
Cricket		Any of various insects of the family Gryllidae (order Orthoptera). Crickets have long antennae and legs adapted for jumping. The males of many species stridulate by rubbing the front wings together. In this way they produce a characteristic shrill chirping sound.
Cricket		A leaping insect which is related to the grasshopper (Orthoptera).
Critical period		The time span during which crops must be kept weed-free to maximise yield.
Crochets		The hooked spines at the tip of the prolegs of lepidopterous caterpillars. Caterpillars of sawflies have prolegs without crochets.
Crop		Community of plants grown to provide feed, food, fibre or other useful commodities.
Crop diversification		Cropping system where a number of different crops are planted in the same area and may be rotated from field to field, year after year.
Crop hygiene		The removal and destruction of infested or diseased plants from a crop so that they do not form a source of infestation for healthy plants. (= Phytosanitation)
Crop loss		A reduction in the quantity and/or quality of the crop yield.
Crop residue		The unused part of the crop that is not harvested. It is usually returned to the land by ploughing (e.g. straw, cornstalks)
Cross vein		A vein connecting adjacent longitudinal veins.
Cross-pollination		Placing or deposition of the pollen from a flower to the stigma of a flower of another plant.
Cross-resistance		A phenomenon that occurs when the development of physiological resistance to a given chemical results in the simultaneous increase in resistance to other chemicals.
Cucurbits		Any of various mostly climbing or trailing plants of the family Cucurbitaceae, which includes the squash, pumpkin, cucumber, gourd, watermelon, and cantaloupe.
Cultivar		A cultivated variety (genetic strain) of a domesticated crop plant.
Cultural control		A method of crop protection using careful timing and a combination of agronomic practices such as tillage, planting, irrigation, sanitation, mixed cropping and crop rotation, which makes the environment less favorable for the proliferation of certain pests or diseases.
Cumulative pesticides		Pesticides that tend to accumulate or build up in the tissues of animals or in the environment (soil, water).
Curative pesticide		A pesticide that can inhibit or eradicate a disease-causing organism after it has become established in the plant or animal.
Curative treatment		Treatment that reduced disease when infection has already taken place.
Cuticle		The noncellular outer layer of the body wall of an arthropod (see: Chitin)
Cutworm		Caterpillars of certain moths (family Noctuidae (Lepidoptera)) that live in the soil. They emerge at night to eat foliage and stems. Cutworms can be serious pests of root crops and of many other crops during the seedling stage.
Damage		The adverse effect on plants or crops due to biotic or abiotic agents, resulting in economic loss (reduction of yield and/or quality).
Damping off		Diseases of seedlings characterized by the rot of seedlings near soil level. This can happen prior to emergence (pre-emergence) or after emergence (post-emergence).
Damselfly		Any of various insects of the suborder Zygoptera (order Odonata). Damselflies are often brightly colored, predatory insects. They have a long slender body and elongated membranous wings that fold together when the insect is at rest.
Dayfly		See: Mayfly.
Dead heart		A symptom of insect damage in which the central shoot of the plant dies.
Decomposer		An organism that utilises dead organic matter as food, decomposing it into more simple substances.
Decontamination		The removal or breakdown of any pesticide chemical from any surface or piece of equipment.
Deficiency disease		A disease resulting from the lack of one or more essential nutrients.
Degree days		Insect development depends on temperature. Below a certain temperature threshold there is no development. Also there is a maximum temperature above which development stops. For a certain day, the number of degree days can be calculated using the threshold and the maximum temperature. If the average temperature of that day is one degree higher than the threshold this will count for one degree day (two degrees above the thresholds is two degree days, etc.) Calculating degree days over a period of time can be used to predict when the development of the insect will be completed.
Delayed toxicity		The effects of a toxic substance may become evident some time after exposure which may delay treatment.
Density dependent		A proportionate increase in mortality (or decrease in fecundity) as population density increases.
Density independent		The mortality or the survival varies independently of population density.
Dentate		Toothed
Deposit		Quantity of a pesticide formulation deposited on a unit area of plant, plant part or other surface at a given application. It may refer to the deposit of the total spray preparation, or it may refer only to the amount of chemical left after the water evaporates.
Dermal toxicity		Toxicity of a chemical substance as a result of contact with the skin.
Dermaptera		Insect order, made up of the earwigs. They are characterized by short, hardened wing covers, chewing mouthparts, pincerlike abdominal cerci, and an incomplete metamorphosis.
Detergents		Wetting agents. Substances that increase the spreading of spray liquids and enable wettable powders to disperse readily in water.
Detoxify		To make an active ingredient in a pesticide or other poisonous chemical harmless and incapable of being toxic to plants and animals.
Detrivores		Animals that feed on dead plant or animal material.
Diapause		A period of dormancy during which the development of the insect is arrested. In the life cycle of many insects, this period of suspended growth and reduced metabolism will make them more resistant to unfavorable environmental conditions such as low temperatures.
Dichotomous key		An identification tool to assist a person in identifying an insect (or other organism). It uses paired statements or questions to guide the user to the solution.
Dicotyledon		Plant having two cotyledons in each seed, e.g. beans. Dicotyledons include flowering plants which are not monocotyledons, the majority of annual weeds and many perennial weeds.
Dictyoptera		Insect order containing the cockroaches and mantids.
Die-back		Necrotic symptom of disease in which death of shoot tissues begins at the tip and progresses backwards to the main stem.
Diluent		Any liquid or solid material serving to dilute or carry an active ingredient. Diluents may aid in mechanical application of a formulated pesticide, but do not directly influence their toxicity (e.g. water in sprays, oils in sprays, finely-ground inert materials in dust).
Dip treatment		The application of a liquid pesticide to a plant by momentarily immersing it, wholly or partially, under the surface of the liquid to coat the plant with the chemical.
Diploid		Cell containing a double set of chromosomes which are arranged in homologous pairs within the nucleus. Most cells in the body are diploids except gametes which have a single set of unpaired chromosomes.
Diplopoda		A class of arthropods. See Millipedes.
Diptera		Insect order containing flies (gnats, mosquitoes, true flies). They are characterized by a single pair of membranous wings, a pair of halters (instead of the hind wings), sucking mouthparts, and a complete metamorphosis.
Disease		The condition of the living plant or animal body or of one of its parts that impairs normal functioning. A disease is characterized by pathological responses called symptoms.
Disease incidence		The frequency of diseased or damaged individuals or their parts. Usually it is the portion of plant units diseased.
Disease intensity		The total amount of disease present.
Disinfect		To free from infection. For example by the destruction of a pest established in or on plants or plant parts.
Dispersal		The movement and spread of individual organisms. Dispersal may be out of a population (emigration) or into a population (immigration).
Dissemination		The transport of inoculum or pest from a diseased to a healthy plant.
Distal		Near or towards the end of an appendage.
Distribution		The geographical area inhabited by a species.
Diurnal		Active during the daytime.
Dormancy		A condition of quiescence or inactivity.
Dorsal		Top or uppermost. Referring to the back or upper side.
Dosage		(= Dose) The quantity of pesticide applied per individual (plant or animal), or per unit area, or per unit volume, or per unit weight.
Dosage-mortality curve		The curve resulting from plotting percentage mortality of test insects over a period of time against dosage of insecticide. (to draw the dosage-mortality curve usually at least four or five doses are used at logaritmic intervals, e.g dosage 1, 2, 4, 8, 16)
Dose		(= Dosage) The quantity of pesticide applied per individual (plant or animal), or per unit area, or per unit volume, or per unit weight.
Doubling time		The time needed for a population to double in size (number of individuals).
Dragonfly		Any of various insects of the suborder Anisoptera (order Odonata). Dragonflies are large insects with a long slender body and two pairs of narrow, net-veined wings. Usually the wings are held outstretched while resting. They feed as predators on small flying insects. Sometimes they are referred to as "mosquito hawk" or "snake doctor".
Drift		Movement by the wind of pesticide droplets or dust beyond the intended area of application.
Drift spraying		Method of applying pesticide aerosol sprays for the control of flying insects.
Drone		A male bee.
Dung		Animal excrement.
Durable resistance		Long lasting resistance of a plant against a pest that is rarely overcome by the pest.
Dust		An insecticide (or pesticide) which is formulated to be used as a dry powder.
Dustable powder		Free-flowing powder pesticide formulation suitable for dusting.
Duster		Equipment for applying pesticides that are formulated as a dust.
Dynamics		In population ecology the study of the reasons for changes in population size. For example: Pest dynamics is the study of changes in pest population size.
Earwig		Any of various insects of the order Dermaptera. Earwigs have an elongate body with a pair of pincerlike appendages protruding from the rear of the abdomen.
Ecdysis		Molting. The process of shedding the exoskeleton. (See: Molt)
Eclosion		The process of hatching from the egg.
Eco-toxicology		The study of toxic effects of chemical substances in living organisms, especially on populations and communities within defined ecosystems. Eco-toxicology includes transfer pathways of these chemicals and their interaction with the environment.
Ecology		Science dealing with living organisms and their relation to the environment. In IPM: The study that deals with the effect of environmental factors, such as soil, climate, natural enemies, etc. on the occurrence, severity and distribution of plant pests. (See also agro-ecology)
Economic damage		The amount of crop injury which will justify the cost of control measures.
Economic injury level		The lowest population density that will cause economic damage. The density of a pest population at which the cost of pest control equals the amount of crop loss caused by the pest.
Economic threshold		The density of a pest population at which control measures are justified to prevent an increasing pest population from reaching the economic injury level. The economic threshold may be expressed in pest numbers or amount of crop damage. (Note: It is not easy to define economic thresholds, as growth of pest populations and resulting damage does not only depend on the size of the pest population but also on other factors, such as crop stage, crop condition, presence of natural enemies, weather, etc. All these factors should be considered together when deciding if control measures are needed.)
Ectoparasite		A parasite that lives on the outside of its host (for example insects which live on the skin of cattle such as ticks, lice and fleas).
Ectoparasitoid		A parasitoid that develops outside its host. It obtains nutrition by penetration of the host's body wall.
Eelworms		Nematodes.
Elytra		Plural of elytron.
Elytron		A thickened, leathery or hard front wing. Present in insects belonging to the orders Coleoptera (beetles) and Dermaptera (earwigs). Plural: Elytra
Embioptera		Insect order, made up of the webspinners. They are characterized by slender bodies, wings absent or membranous, chewing mouthparts, and an incomplete metamorphosis.
Emergence		Insects: The process of the adult insect leaving the pupal case or the last nymphal skin. Seeds: Germination of a seed and the appearance of the first leaves of the crop plant above the ground.
Emigration		The movement of individuals out of a population.
Emulsifiable Concentrate		(= e.c.) A liquid pesticide formulation that when added to water spontaneously disperses as fine droplets to form a stable emulsion.
Emulsifier		A substance that promotes the suspension of one liquid in another. Emulsifiers are often added to pesticide formulations (for example to mix oil based pesticide formulations in water).
Endangered species		An animal or plant species threatened with extinction.
Endemic species		A species that occurs only in one very restricted area, such as an island or a mountain range.
Endoparasite		A parasite that lives inside its host.
Endoparasitoid		A parasitoid that develops within its host.
Endopterygota		Subclass of the insects including the orders with a complete metamorphosis. In these insects the external (and internal) changes during the life history are the greatest. The eggs hatch into larvae which feed actively during the different instars. The larvae may or may not have legs. The development of wings is not visible during the larval stages. After several molts a pupa is formed. A pupa is an inactive stage, it does not feed and it does not move. Sometimes the pupa is protected by a cocoon of silk, or it is found in an earthen cell in the soil. During this pupal stage big changes take place internally. After the pupal stage, a highly active winged adult appears. Often, the larvae and the adults live in different types of habitat and use different types of food.
Entomologist		A person who studies the biology of insects.
Entomology		The study of insects.
Entomophagous		Feeding on insects.
Environmental pollution		Undesirable levels of pesticides in air, soil, water, vegetation, animals and man.
Ephemeroptera		Insect order, made up of the mayflies. They are characterized by membranous wings, nonfunctional mouthparts, two or three abdominal cerci, and an incomplete metamorphosis.
Epidemic		A widespread and severe, temporary increase in the incidence of an infectious disease, particularly within a season.
Epidemiology		The science of disease in populations. The study of the development and spread of disease and of the factors affecting these processes.
Epiphyte		Non-parasitic plant that is attached to another plant for mechanical support only. For example: orchids, lichens and mosses that are growing on trees.
Erosion		The wearing away of the land surface by water and wind.
Exopterygota		Subclass of the insects including the orders with a simple or incomplete metamorphosis. In molting from egg, via the nymphal stages to an adult, there is a gradual change in the external appearance. The late nymphal stages already show the development of wing pads. But only in the last molt functional wings are developed. The nymphs usually have the same feeding habits as the adults.
Exoskeleton		A skeleton or supporting structure on the outside of the body. Present in all members of the Arthropoda.
Exotic		Alien. Introduced from another country.
Exotic species		An organism that evolved in one part of the world and that now occurs either accidentally or intentionally in a new region. Opposite: native species.
Extension		All methods, techniques and activities aimed at the dissemination and proliferation of agricultural information in rural communities, which make such information more easily accessible to desired target groups such as small farmers, pest control operators, and agricultural students.
Extermination		Complete extinction of a species over a large continuous area such as an island or a continent.
Exuviae		The cast skin of an arthropod.
F1		The first-generation offspring of a given mating.
F2		The second-generation offspring of a given mating.
Facets		The individual units that compose a compound eye.
Fallow		Plowed but left unseeded during a growing season.
Family		A subdivision of an order, containing a group of related genera. Family names always end in "idae", for example Meloidae.
Farmyard manure		Cattle droppings (faeces) mixed with straw or similar material used as bedding in sheds, barns or night yards. Farmyard manure is often heaped and left to rot well before using it as an organic fertilizer in crop fields. It helps to improve water-retaining properties of soils.
Fauna		All of the animals found in a given area.
Fecundity		The reproductive capacity of an organism.
Femur		The third leg segment, located between the trochanter and the tibia.
Fermentation		The process of growing a selected organism, usually a bacterium, mould or yeast, on substrate so as to bring about a desired change or to generate products of the cells' metabolism. For example ethanol and carbon dioxide are produced from yeast fermentation.
Fertile		Capable of producing offspring.
Fertilization		In soil: The application of nutrients (fertilizer) to soil in order to promote growth and development of crop plants.
Fertilizer		Substance added to soil to make it more fertile.
Fetotoxin		A substance that can poison the foetus (child developing in the womb).
Filiform		Hairlike or threadlike (often referring to the antennae).
Flea		Any of various insects of the order Siphonaptera. Fleas are small, wingless, bloodsucking insects that have legs adapted for jumping. They are parasitic on warm-blooded animals.
Flea beetle		Any of various beetles of the subfamily Alticinae (family Chrysomelidae, order Coleoptera). They are small leaf-feeding beetles that have hind legs adapted for jumping.
Flora		All of the plants found in a given area.
Fly		Any of numerous two-winged insects of the order Diptera, especially any of the family Muscidae. Examples of true flies are the house fly and the tsetse fly. The true flies (order Diptera) should not be confused with other insects that are called "flies", such as caddisfly, butterfly, and dragonfly, that belong to other insect orders.
Fog treatment		The application of a pesticide as a fine mist for the control of pests.
Foliar application		Application of a pesticide to the leaves or foliage or plants.
Foliar spray fertilizers		Nutrients sprayed in solution on to leaves.
Food chain		Sequence of species within a community. Each member serves as food for the next higher species in the chain. For example: - plants, herbivores, carnivores. - grass, cow, man - cabbage, caterpillar, bird
Foot rot		Rotting that involves the lower part of the stem-root axis, but not the distal parts of the roots.
Forensic entomology		The application of the science of entomology to answer questions of interest to the legal system, for example in relation to a crime or to a civil action.
Form		A subdivision within a species or variety.
Forma specialis		Special form. Biotype (or group of biotypes) of a species of pathogen that differs from others in the ability to infect selected genera or species of susceptible plants. Forma specialis can be abbreviated as f. sp.
Formulation		Way in which basic pesticide is prepared and sold for use. A formulation contains the active ingredient(s) and other substances such as carriers and stickers. Examples of formulations include: emulsifiable concentrates, wettable powders, suspension concentrates, dusts, baits, fumigants, aerosols and granules.
Frass		Plant fragments made by plant-feeding insects, usually mixed with excrement.
Frenulum		A bristle or group of bristles on the hind wings of certain moths and butterflies that holds the forewings and hind wings together during flight.
Fruit fly		Any of various small flies of the family Drosophilidae (order Diptera). The larvae feed on ripening or fermenting fruits and vegetables or Any of various flies of the family Tephritidae (order Diptera). The larvae hatch in plant tissue.
Full-sib		Having both parents in common.
Fumigant		Liquid or solid chemical that forms vapours that kill organisms. Fumigants are often used in the treatment of areas difficult to penetrate with sprays or other pesticidal formulations.
Fumigation		The application of a fumigant for disinfestation of an area.
Fungicidal		Killing fungi.
Fungicide		Substance that kills or inhibits the development of fungus spores or mycelium.
Fungicide resistance		A decrease in sensitivity to a fungicide. Fungicide resistance is the result of selection or mutation following exposure to the fungicide
Fungus		Plural: Fungi Non-chlorophyll-bearing plants of a lower order than mosses and liverworts). Fungi often show mycelial, spreading growth. Some fungi can be disease causing organisms of plants. Others live on dead plant material and play a role as decomposers. Examples of fungi: rusts, smuts, mildews, moulds and yeasts.
Gall		An abnormal growth (tumor) of plant tissues caused by the stimulus of certain insects, bacteria, fungi or mites.
Gaster		The rounded part of the abdomen behind the nodelike segment or segments (in ants).
Gene-for-gene resistance		Vertical resistance.
Genera		Plural of genus.
General use pesticide		A pesticide that can be purchased and used by the general public See also: Restricted-use pesticide.
Generation		The period from any given stage in the life cycle to the same stage in the offspring.
Genetic control		A method of pest control which makes use of selected strains of the target species that possess genetic abnormalities. When released into the target population they mate with wild individuals and produce sterile offspring. See also: sterile insect technique
Genus		A group of closely related species. Subdivision of a family. Genus names are written with a capital and should be printed either in italics or underlined. Plural: Genera.
GMO		Genetically Modified Organism. An organism whose genes have been deliberately manipulated.
Gonopore		The external opening of the reproductive organs.
Grafting		A method of plant propagation by transplantation of a bud or a scion of one plant on another plant. The joining of cut surfaces of two plants so as to form a living union.
Gramineae		A family of plants. Grasses (including cereals).
Granule		Particle of inert material which is mixed or impregnated with a pesticide.
Grass		Plant belonging to the family Gramineae.
Grasshopper		Any of numerous insects of the families Acrididae and Tettigoniidae (order Orthoptera). Grasshoppers usually have long, powerful hind legs adapted for jumping.
Gravid		Pregnant.
Grease band		Adhesive material applied as a band round the tree trunk to trap insects.
Green manure		A crop grown and ploughed under to improve the soil.
Greenbug		The common name for certain species of aphids that feed on crop plants.
Gregarious		Living in groups.
Growth regulators		Organic substance that are effective in minute amounts for controlling or modifying growth processes in plants or insects. For example: plant hormones.
Growth stage		A morphologic phase of plant or crop development that can be easily recognised in the field. For example: seedling stage, tillering stage, flowering stage, etc.
Grub		A thick-bodied larva of a beetle with thoracic legs and a well developed head. The body is curved, C-shaped.
Grubbing		Digging out roots.
Grylloblattodea		Insect order containing the rock crawlers.
Gum		Sticky substance formed by cells in reaction to wounding or infection (usually in trees).
Gummosis		Production of gum by plant tissues.
Habitat		A place with a particular kind of environment where plants and animals live.
Half-sib		Having one parent in common.
Halter		A small knob-like balancing organ located in place of the hind wing in the order Diptera (true flies).
Harmful organisms		Pests. Includes vertebrate and invertebrate pests, pathogens and weeds.
Hatch		To break out of the egg.
Hazard		The probability that a substance will cause harm under conditions of exposure.
Head		In insects: The frontal body region, which bears the antennae, eyes, and mouthparts.
Heading stage		Growth stage of grain crops when the seed head of a plant begins to emerge from the sheath.
Hemelytron		Front wing with a thickened basal part and a membranous tip.
Hemimetabola		Insects having a simple metamorphosis. For example in the Orthoptera, Heteroptera and Homoptera. See: Incomplete metamorphosis.
Hemimetabolous metamorphosis		Gradual metamorphosis in insects, in which the nymphs are generally similar in body form to the adults and become more like the adults with each instar.
Hemiptera		In some classifications this is an insect order containing two suborders; Heteroptera and Homoptera. Other classifications consider the Heteroptera and the Homoptera as separate orders.
Herbicide		Substance used for preventing, destroying or controlling weeds..
Herbivore		Plant eating. An organism that feeds on plant material (see also carnivore and omnivore).
Herbivorous		Feeding on plants (see also: phytophagous and carnivorous).
Hermaphrodite		Bisexual. In flowering plants: both stamens and carpels are present in the same flower In animals: An individual with both male and female gametes.
Heteroptera		Order of insects containing the bugs.
Hexapoda		Insects. A class within the phylum Arthropoda
Hibernate		Overwinter. Spend the winter in a dormant condition.
Hibernation		A type of dormancy that occurs during the winter.
Holometobola		Insects with complete metamorphosis. The life cycle includes egg, larva, pupa and adult.
Homoptera		Order of insects containing cicadas, hoppers, psyllids, whiteflies, aphids and scale insects. They are characterized by uniformly leathery or uniformly membranous forewings, sucking mouthparts, and an incomplete metamorphosis.
Honeydew		A liquid discharged by certain insects that is high in sugar content (aphids, scale insects, mealybugs).
Horizon		In soil: A layer of soil, roughly parallel to the surface of the soil, with distinct characteristics which were produced by soil-forming processes.
Horizontal resistance		Resistance that does not involve a gene-for-gene relationship Opposite: Vertical resistance.
Hormone		A chemical agent that controls various physiological processes within an organism (plant or animal).
Hornworm		Larvae of the family Sphingidae (Hawkmoths). A caterpillar with dorsal spine or horn on the last abdominal segment.
Host		The plant on which an insect feeds. The organism in or on which a parasite lives. Organism that furnishes food, shelter or other benefits to another organism of a different species. For example: Cabbage is a host for the Diamond-back moth.
Host plant resistance		A method of pest control in which resistant crop plants are used.
Host range		The various kinds of host plants that may be attacked by a pest.
Humus		The well-decomposed, more or less stable part of the organic matter of the soil.
Hyaline		Transparent, colourless.
Hydroponics		The growing of plants in aqueous chemical solutions.
Hymenoptera		Insect order containing bees, wasps, ants, and sawflies. They are characterized by membranous wings, chewing or chewing-lapping mouthparts, and a complete metamorphosis.
Hypermetamorphosis		A kind of complete metamorphosis in which the different larval instars represent two or more different types of larva. During the various larval stages the morphology can change, for example from that of a campodeiform larva (elongate and flattened body with well-developed legs and antannae) to a scarabaeiform larva (grublike) or to a vermiform larva (maggotlike).
Hyperparasite		A parasite whose host is another parasite.
Hypha		One of the simplest branched filaments of the mycelium of a fungus that is composed of one or more cylindrical cells and that increases in length by growth at its tip. New hyphae arise as lateral branches. Plural: Hyphae
Hyphae		Plural of Hypha.
Hypocotyl		The stem of the embryo or young seedling below the cotyledons.
Imago		The adult stage of an insect. The reproductive stage.
Immature		A developmental stage preceding the adult stages. For example caterpillars and pupae are immature stages.
Immunotoxin		A substance that damages the immune system.
In vitro		Refers to a situation where micro-organisms are kept or propageted in isolation of their natural hosts or other living organisms. In vitro means: In glass (referring to e.g. test tubes) Contrast with: in vivo.
Inchworm		See: Looper.
Incomplete metamorphosis		A moderately complex type of insect development with three distinct stages; egg, nymphal stages, and adult. An incomplete metamorphosis is characteristic for insect orders belonging to the exopterygota.
Inert		A substance having no biological action.
Inert ingredient		Any substance in a pesticide formulation that has no pesticidal action.
Infect		Of a parasite or pathogen, to enter and grow, or to replicate, within plant tissues.
Infection		The introduction or entry of a parasite or pathogenic micro-organism into a susceptible host, resulting in the presence of that organism within the body of the host, whether or not this causes pathologic effects.
Infectious disease		A disease caused by a living organism.
Infest		In insects: to occupy and cause damage. In soil: to contaminate by fungi, eelworms or insects . To introduce a pathogen into the environment of a host.
Infestation		Presence of animal pests (insects, rodents, etc.) on the plant crops.
Inflorescence		The flowering portion of a plant.
Ingest		To eat or swallow.
Injury		Damage of a plant which impairs growth, functioning or appearance, but not necessarily resulting in loss of yield or quality.
Inorganic compound		A compound which does not contain carbon atoms. Except CO2, which is considered an inorganic compound.
Insect		Insects are animals belonging to the class Hexapoda. They have a segmented body with three distinct regions; the head, the thorax, and the abdomen. The head bears one pair of antennae, compound eyes, and the mouthparts. The thorax bears three pairs of legs (one on each of the three thoracic segments). The thorax bears often one or two pairs of wings (on the second and/or third thoracic segments). A gonopore is present at the posterior end of the abdomen.
Insect growth regulator		Chemical substance which disrupts the action of insect hormones that control processes such as moulting, development from pupa to adult, etc.
Insecticide		Chemical substance used for killing insects. The term insecticide usually includes all substances intended for preventing, destroying or repelling any member of the class Hexapoda (insects) or related classes in the phylum Arthropoda.
Insectivorous		Feeding on insects.
Instar		The insect between two successive molts. The first instar is the larva which hatches from the egg.
Integrated control		The combination of several different methods of pest control.
Integrated Pest Management		Sometimes referred to as Integrated Pest Control. A pest management system that, in the context of the associated environment and the population dynamics of the pest species, utilizes all suitable techniques and methods in as compatible a manner as possible and maintains the pest population at levels below those causing economic injury. Often, the term IPM includes all elements contributing to an effective, safe, sustainable and economically sound crop protection system. Abbreviation: IPM
Intercropping		The growing of two or more crops simultaneously in the same field.
Intermediate host		Host in which a parasite develops to some extent but not to sexual maturity.
Interplanting		The interplanting of one crop within another, for example with the purpose of trapping or repelling pest insects.
Intoxication		Poisoning. The adverse effect due to the intake of or exposure to any substance.
Invertebrate		Animals, not having a backbone or spinal column (molluscs, arthropods, worms, etc.)
IPM		Integrated Pest Management
Isoptera		Insect order containing termites. They are characterized by membranous wings (or wingless), beadlike antennae, chewing mouthparts, and an incomplete metamorphosis.
Joint		The articulation between two segments, body parts, or appendages.
Jointing stage		Growth stage of grain crops when the internodes of the stems are elongating.
Kairomone		A chemical or mixture of chemicals emitted by an organism (e.g. a plant) that induces a response in an individual of another species (e.g. an insect) that is beneficial to the receiving organism. For example a plant scent that makes the plant more easily identifiable to an insect pest.
Labium		Lowerlip. Unpaired set of mouthparts of insects located ventrally. The labium has 2 pairs of segmented palps.
Ladybird		Bright colored beetle in de Coccinellidae family (order Coleoptera). Most species of ladybirds are predatory insects (both the adults and the larvae). They feed on aphids and other small insects and play an important role in biological control of certain pests. (Synonym: Ladybug)
Land-races		Varieties of plant species selected by farmers on a local basis over many years, which are strongly adapted for local conditions.
Larva		The immature stage between egg and pupa of insects with a complete metamorphosis. (see also: Nymph)
Larvicide		Chemical substance that destroys larvae of a pest.
Latent		Concealed. Not clearly visible.
Lateral		Referring to the side (left side or right side).
LC50		Lethal Concentration 50%. Concentration required to kill 50% of test organisms.
LD50		Lethal Dose 50%. The dose required to kill 50% of test organisms.
Leaching		The movement of a pesticide or other chemical downward through the soil as a result of water movement.
Leaf insect		Insect in the order Phasmida. Stick insects resemble sticks. Leaf insects (in the same order) look like leaves.
Leaf miner		An insect that lives between the lower and upper surface of a leaf feeding on the leaf cells. For example the larvae of Agromyzidae (Diptera).
Leaf roller		Any of several moths of the family Tortricidae (order Lepidoptera). The caterpillars make nests of rolled leaves and silk.
Leaf scorch		Leaf necrosis, usually marginal, due to phytotoxicity or nutrient deficiency.
Legislative control		The use of legislation to control the importation and to prevent any spread of a pest within a country.
Legume		Plant belonging to the family Leguminoseae. Legumes contains root nodules and are capable of symbiotic nitrogen fixation with bacteria of the genus Rhizobium. Examples of legumes: beans, peas.
Lepidoptera		Insect order containing butterflies and moths. They are characterized by scale-covered wings, coiled siphoning mouthparts, and a complete metamorphosis. The coiled tongue is also called proboscis.
Lesion		Any break in the epidermis of a plant or a localised, diseased or disordered tissue.
Lethal Concentration 50%		(= LC50) Concentration required to kill 50% of test organisms.
Lethal Dose 50%		(= LD50) Dose required to kill 50% of test organisms.
Lice		Plural of louse.
Lichen		A regular association of an alga with a fungus.
Life cycle		The sequence events in the development of an insect that occur from birth (hatching of the egg) to reproduction (mating and egg laying).
Local infection		An infection affecting only a limited part of the plant.
Locust		Any of numerous grasshoppers of the family Acrididae (order Orthoptera). Locusts are often migrating in huge swarms that consume vegetation and crops.
Longitudinal		Lengthwise of the body or of an appendage (leg, wing, antenna, etc.)
Looper		A caterpillar belonging to the family Geometridae. Loopers have only one pair of abdominal prolegs (besides the terminal claspers). They move with a characteristic looping of the body. Other common names for Loopers are Measuringworm or Inchworm.
Louse		Any of numerous insects of the orders Mallophaga or Anoplura. Lice are small, flat-bodied, wingless biting or sucking insects. Many species are external parasites on various animals, including human beings.
Maggot		Larva of Diptera. They are legless, soft-bodied, and do not have a distinct head capsule. Often they are found in decaying matter.
Malaise trap		A tent-like trap made out of netting used to catch flying insects.
Malaria		A human disease caused by a single-celled protozoan parasite called Plasmodium. This disease is carried and spread by mosquitoes of the genus Anopheles. (See: Vector)
Mallophaga		Insect order, made up of the chewing lice. They are characterized by flattened, wingless bodies, chewing mouthparts, and an incomplete metamorphosis.
Mandible		Jaw. One of the anterior pair of paired mouthpart structures. Mandibles are clearly visible in insects with chewing mouthparts, such as grasshoppers, cockroaches, beetles and ants.
Manejo Integrado de Plagas		(Abbreviation: MIP) This is the Spanish equivalent of Integrated Pest Management (IPM).
Mantid		Insect belonging to the family Mantidae (order Dictyoptera). Mantids are large, elongate insects with enlarged front legs that are adapted for grasping their prey (other insects). They have an incomplete metamorphosis.
Mantis		Insect belonging to the order mantodea. Mantis or Praying mantis are insects which holds the forelegs in an upright folded position as if in prayer.
Mantodea		Insect order which includes the Praying mantis.
Maxilla		Jaw, upper jawbone. One of a pair of mouthparts characteristic of chewing insects. The maxilla has lobes and bears a multi-segmented palp. Maxillae are used for grasping and tasting of food.
Mayfly		Any of various insects of the order Ephemeroptera. Mayflies are fragile winged insects that develop from aquatic nymphs. In the adult stage they live no longer than a few days. Sometimes they are called "dayfly".
Mealworm		Common name for the slender larvae of the beetle family Tenebrionidae (Darkling beetles). They are generally found in grains and cereals.
Mealybug		Any of various insects of the family Pseudococcidae (suborder Homoptera; order Hemiptera). These are small wingless insects that have the body covered with a white powdery waxy substance.
Measuringworm		See: Looper
Mecoptera		Insect order, made up of the scorpionflies. They are characterized by membranous wings, elongate faces with chewing mouthparts, a scorpion-shaped abdomen (male only), and a complete metamorphosis.
Membranous		Like a membrane. Often referring to thin, mostly transparent, insect wings.
Mesothorax		The middle, or second, segment of the thorax.
Metamorphosis		A change in form during the development. After hatching from the egg, an insect grows by a series of molts. After shedding the old skin they expand into a new larger one. This molting continues until the adult stage is reached. At each molt, some externally visible changes occur. This type of growing is called metamorphosis. The division of insects into apterygota, exopterygota and endopterygota is mainly based on differences in the type of metamorphosis. (see also: Complete metamorphosis, Incomplete metamorphosis)
Metathorax		The posterior, or third, segment of the thorax.
Microbial control		Control of insects (or other organisms) by the use of micro-organisms (including viruses).
Microbial insecticide		A pathogenic micro-organism or its products (toxins etc.) that is applied in the same way as a conventional pesticide to control a pest population. Similar terms: microbial pesticide, biotic insecticide, microbial control product.
Microbial pesticides		Living micro-organisms, such as fungi, bacteria, viruses, protozoa and nematodes, as well as metabolites produced by micro-organisms that are used in pest control. For example: Bacillus thuringiensis, Trichoderma sp.
Mildew		Disease causes by a fungus and characterised by the appearance of a white, mycelial growth and spores on the surface of infected plant parts.
Millipedes		Animal belonging to the class Diplopoda. Some characteristics of millipedes are, a cylindrical, two-parted body (head and many-segmented trunk), one pair of antennae and the trunk segments each bearing two pairs of legs.
Mimicry		The resemblance of an insect to its natural surroundings, providing some protection from enemies.
Mine		Deep hole or tunnel in a plant part caused by burrowing insects or their larvae (e.g. stemborers, leafminers).
Miticide		(= Acaricide) Pesticide that can kill mites, ticks and spiders.
Molluscicide		A pesticide used to kill or control snails and slugs.
Molt		Ecdysis. The process of shedding the exoskeleton. To shed the exoskeleton.
Moniliform		Beadlike, with rounded segments. (often referring to antennae)
Mosquito		Any of various two-winged insects of the family Culicidae (order Diptera). In most species the female is distinguished by a long proboscis for sucking blood. Some species of mosquitoes are vectors of diseases such as malaria and yellow fever.
Mosquito hawk		See: Dragonfly.
Mosquito net		A fine net or screen used to keep out mosquitoes.
Moth		Any of numerous insects of the order Lepidoptera. Moths are generally distinguished from butterflies by their nocturnal activity, hairlike or feathery antennae, stout bodies, and the frenulum that holds the front and back wings together. (See also: Butterfly)
Mottle		A pattern of indistinct light and dark areas on plant tissue. Usually a symptom of virus diseases.
Mould		A fungus which grows as hyphae interwoven into an extensive mycelium. Moulds usually occur on decaying matter or on plant surfaces.
Mulch		Material used to form a covering over the soil, usually to prevent evaporation of soil moisture. For example rice straw can be used as a mulch to cover the soil between individual vegetable plants.
Mutagen		A substance that causes mutation in cells.
Mutation		A suddenly occurring heritable change in DNA. Mutations may be brought about by chemical or physical agents (mutagens) or as a result of an accidental change in genes.
Mycelium		The vegetative structure of a fungus, made up of hyphae.
Mycology		The study of fungi.
Mycoplasma		A micro-organism intermediate in size between viruses and bacteria. Mycoplasma possess many virus-like properties.
Myriapods		Arthropods with many legs, such as the centipedes and millipedes.
Naiad		Larva of a dragonfly or damselfly (Odonata). Naiads are aquatic larvae.
Natural control		The collective action of environmental factors to maintain a pest population size at an acceptable level over a period of time.
Natural enemy		An animal or plant which kills or injures another animal or plant. For example predators, parasites and pathogens that attack pests.
Natural host		A host in which the pathogenic micro-organism or parasite is commonly found and in which it can complete its development.
Natural selection		Selection among a group of animals or plants by the forces of nature. It allows those of the group best fitted to survive in the particular environment to live and reproduce, while those not fitted to that environemnt will die. By this means, the species or group gradually adapts to the environment as poorly adapted individuals are gradually eliminated over many generations.
Necrosis		A localised and rapid destruction of a cell or group of cells. For example rot and canker are necrotic symptoms.
Necrotic		Having symptoms characterised by the death or disintegration of cells or tissues.
Nematicide		Chemical used to kill nematodes.
Neuroptera		Insect order, containing the dobsonflies, fishflies, alderflies, owlflies, snakeflies, antlions, and lacewings. They are characterized by membranous wings, chewing mouthparts, and a complete metamorphosis.
Neurotoxin		A substance that damages nerves or the nervous system.
Nilaparvata lugens		Brown planthopper (BPH). It is a small cicada that can destroy rice crops (hopperburn).
Nit		The egg of a louse, which is glued to the hair of its host.
Nocturnal		Active at night.
Nodule		A tumor-like structure produced by the roots of nitrogen-fixing plants. The nodules contain symbiotic nitrogen-fixing microbes. Nodules can be found for example in legumes.
Non-infectious disease		A disease which cannot be transmitted from one plant to another. It is not caused by a pathogen but by an environmental factor.
Non-persistent virus		A virus that persists in its vector for only a few hours (usually less than 4 hours).
Non-target organisms		Those organisms which are not the intended targets of a particular use of a pesticide.
Notum		The dorsal or top surface of a body segment (often referring to the segments of the thorax).
NPV		Nuclear polyhedrosis virus
Nuclear polyhedrosis virus		A disease cuasing virus of insects, mainly the larvae of certain Lepidoptera and Hymenoptera. Abbreviated as NPV. Certain types of NPV are cultured commercially and sold as microbial insecticides.
Nutrient		A substance needed by plants and animals for life and growth.
Nymph		An immature stage of an insect that does not have a pupa stage. (See also: Incomplete metamorphosis)
Occasional pest		A pest generally under natural control. It causes economic damage only sporadically or in localised areas.
Ocellus		A simple eye of an insect or other arthropod. Ocelli are often present on the head of spiders and insects.
Odonata		Insect order, including the dragonflies and damselflies. They are characterized by membranous wings, bristlelike antennae, long, slender bodies, chewing mouthparts, and an incomplete metamorphosis.
Ommatidium		A single unit or visual section of a compound eye.
Omnivore		Organisms that feed on material of both plant and animal origin (see also carnivore and herbivore).
Omnivorous		Both carnivorous and herbivorous. Eating meat and vegetation.
Ootheca		The covering or case of an egg mass of certain insects in the orders Orthoptera (grasshoppers) and Dictyoptera (cockroaches, mantids).
Opisthogoneate		Having the genital opening situated terminally, at the posterior end of the body.
Oral toxicity		The toxicity of a compound when ingested. The oral toxicity of a pesticide is expressed in milligrams of chemical per kilogram of body weight. It is the amount which when given orally in a single dose will kill 50% of the animals. See also: LD50
Order		A subdivision of a class containing a group of related families; the class Hexapoda (insects) contains about 30 different orders.
Organic compound		A compound which contains one or more carbon atoms. Except CO2 which is not considered an organic compound.
Organic matter		The fraction of the soil composed of carbon based materials.
Organochlorine insecticide		One of the many chlorinated hydrocarbon insecticides. For example: DDT, dieldrin, chlordane, BHC, Lindane.
Organophosphate		Class of insecticides derived from phosphoric acid esters. Organophosphates inhibite the functioning of the enzyme cholinesterase.
Orthoptera		Insect order containing grasshoppers and crickets. They are characterized by leathery forewings, chewing mouthparts, and a gradual metamorphosis. Usually the hindlegs are enlarged and adapted for jumping.
Ovicide		Pesticide that destroys eggs. Also: Ovacide
Oviparous		Reproduction by laying eggs.
Oviposit		To lay or deposit eggs.
Ovipositor		The external genitalia of a female insect, used for laying eggs.
Paddy		Rough rice. The rice kernel with the husk on.
Palpus		Paired segmented appendage on the maxilla (maxillary palp) or on the labium (labial palp) of insects. Also called palp.
Parasite		An animal that lives in or on the body of another living animal (the host) at least during a part of its life cycle. It feeds on the tissues of the host. Entomophagous insect parasites usually kill their host in the end.
Parasitism		Symbiosis in which the symbiont benefits from the association, whereas the host is harmed in some way.
Parasitoid		Any of various insects, such as the ichneumon fly, whose larvae are parasites that eventually kill their hosts.
Parthenogenesis		Reproduction without fertilization.
Pathogen		A disease-causing microorganism; a bacterium or virus.
Pathology		The science that deals with all aspects of diseases.
Peat		A type of soil consisting of partly decomposed organic matter that has accumulated under excessive moisture.
Pedicel		The second segment of an insects' antenna. The stem of the abdomen, between the thorax and the gaster (in ants).
Pedipalp		One of the second pair of appendages near the mouth of a spider or other arachnid. Pedipalps can be modified for various functions: reproductive, predatory, or sensory.
perivisceral sinus		A cavity inside the body surrounding the viscera (internal organs).
Persistence		The characteristic of chemicals or microbial insecticides that remain active for a long period of time after application. In chemicals, persistence is the result of low volatility and chemical stability. Certain organochlorine insecticides such as DDT are highly persistent.
Pest		An animal causing damage or annoyance to man, his animals, crops or possessions, such as insects, mites, nematodes, rodents, birds. In phrases such as 'integrated pest management' and 'pest control', the term is used in a broader sense to mean all harmful organisms including fungi, bacteria, viruses and virus-like organisms, and weeds.
Pest insect		An insect causing damage to man's crops, domestic animals or possessions. (See: Pest)
Pest intensity		The total number of pests per unit of habitat or area.
Pest spectrum		The complete range of pests attacking a particular crop.
Pesticide		Any substance (chemical or microbial) which because of its toxicity is used to control pests. Pesticides include: acaricides, bactericides, fungicides, herbicides, insecticides, nematicides, rodenticides, etc.
Pesticide resistance		Genetically selected tolerance of pest populations to pesticides. Resistance is caused by the repeated exposure of the pest population to pesticide treatment. Sensitive individuals are killed, while the resistant individuals will continue to reproduce. Resistance can develop to both chemical and microbial pesticides.
Petiole		Stalk or stem. The stalk or stem by which the abdomen is attached to the thorax (wasps and ants).
Phasmida		Insect order, made up of the walking sticks and leafinsects, characterized by short leathery wings (or wings absent), chewing mouthparts, slender body, and an incomplete metamorphosis.
Pheromone		Chemical(s) used for communication between individuals of a given species.
Pheromone trap		An insect trap in which dispensers with insect pheromones are used as an attractant. Usually the inside surface of the traps is covered with glue to prevent escape.
Photoreceptor		Receptor which perceives light stimulus. Adults and nymps of insects have often two compound eyes and up to three simple eyes on their head.
Phyllotreta		A genus within the Chrysomelidae family (in the order Coleoptera = Beetles).
Phylum		Major subdivision of the animal kingdom. (plural = Phyla). Some examples of animal phyla are; Protozoa (single-celled animals) Nemathelminthes (roundworms) Arthropoda (crayfish, millipedes, centipedes, spiders, and insects) Chordata (fish, amphibians, reptiles, birds, mammals)
Physical control		The use of mechanical and physical methods of controlling pests (e.g hand pick, heat treatment, radiation).
Phytophagous		Feeding on plants. Herbivorous.
Phytosanitation		The removal and destruction of infested or diseased plants from a crop so that they do not form a source of infestation for healthy plants.
Phytotoxic		A material which causes damage to plants.
Pitfall trap		A trap for catching ground crawling insects. Usually it is made out of a cuplike container buried in the ground into which insects fall. The beaker contains a liquid (water with soap; alcohol) or glue to prevent escape.
Plant louse		See: Aphid.
Plant nutrient		A chemical compound used by plants for growth, development or reproduction.
Plant pathology		The study of plant diseases.
Plecoptera		Insect order, made up of the stoneflies. They are characterized by membranous wings, chewing mouthparts, two short abdominal cerci, and an incomplete metamorphosis.
Pleuron		A lateral region on the sides of the body of certain arthropods (Plural: Pleura).
Poison		Any chemical or agent that can cause illness or death when eaten, absorbed through the skin, or inhaled by humans or animals. See: Pesticides.
Poison bait		Attractant foodstuff for animal pests (insects, molluscs, rodents) mixed with a pesticide to kill them.
Pollen		The male germ cells produced in the anther of flowers.
Pollination		The transfer of pollen from the male anther to the female stigma of a flower. Self-pollination: Pollen is carried between anther and stigma of the same flower is called self-pollination Cross-pollination: Pollen is carried from the flower of one plant to another plant of the same species.
Population density		The number of individuals of one population per unit area or volume.
Population dynamics		The study of changes in population size over time.
Post-harvest		The period between maturity of the crop and its consumption.
Posterior		Hind or rear.
Predator		An animal that attacks and feeds on other animals (the prey). The prey is killed and usually mostly or entirely eaten.
Predator control