Tree Fruit Research & Extension Center

Orchard Pest Management

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Abdomenthe posterior most of the three main body divisions of insects.
Abscissionthe normal separation of fruit and leaves from plants by the development of a thin layer of pithy cells at the base of their stems.
Acaracidea chemical used to control mites; also called a miticide.
Adeagusthe intromittent organ of a male insect; the penis.
Alatehaving wings.
Analogthat which is similar or corresponds with something else; in chemistry, two compounds with similar compositions and structures.
Antennasegmented sensory organs located on the head above the mouth parts.
Arachnidany of a large class of arthropods that have four pairs of legs and breathe through lung-like sacs or breathing tubes. Some, such as mites, have bodies without exterior segmentation. Others, such as spiders, have bodies divided into two segments. Others have bodies of several segments.
Arrhenotokyparthenogenesis in which only male offspring are produced.
Arthropodany member of a large taxon of invertebrate animals with jointed legs and a segmented body; such as insects, crustaceans and arachnids.
Axilthe upper angle formed by a leaf and the stem from which it grows.
Biofixa biological fix point used to synchronize a degree-day model with insect development, such as the first capture of moths in a pheromone trap.
Cambiumthe layer of formative cells between the wood and bark in woody plants. The cells grow to form new wood and bark.
Chalcid waspa large family of very small wasps. In many cases the larvae are parasites on the eggs, larvae or pupae of other insects.
Clypeusa shield-like plate on the anterior part of the head of certain insects.
Confidence interval (CI)in statistics, the estimated mean, plus or minus a range within which one is confident that the true mean occurs. For instance, for a 95% confidence interval of 2.0 plus or minus 0.4, the estimate of the mean is 2, and if you were to repeat the experiment 100 times, in 95 of those experiments the estimated mean would fall between 1.6 and 2.4.
Corniclesthe protruding dorsal tubes on aphids that secrete a waxy substance.
Deutonymphthird instar of an immature tetranychid mite
Diapausea period of delayed development or growth accompanied by reduced metabolism and inactivity.
Dorsalpertaining to the back or upper side of the body.
Ecdysisthe process of shedding the old skin (cuticle).
Ecdysone(“molting or prothoracic hormone”) a hormone produced in the prothoracic gland that initiates growth and molting activities of the epidermal cells.
Eclosionthe act of the insect leaving the egg or emergence of the adult at the terminal molt.
Ecosystema system made up of a community of animals, plants and bacteria, and its interrelated physical and chemical environment.
Ectoparasitoida parasitoid that lives on the outside of its host.
Elytra (plural of elytron)the front pair of thickened wings in beetles, which form a protective covering for the rear wings.
Endoparasitoida parasitoid that lives inside its host.
Epidermisthe outer layer of skin of an insect, or the outermost layer of cells of a plant.
Exoskeletonthe hard, external, secreted supporting structure of an insect; an external skeleton.
Exuviathe “cast skin” of an arthropod.
Fecunditythe rate at which a female produces eggs.
Flaggingwilting of foliage.
Frassrefuse or excrement left by insect larvae.
Gasterthe abdomen of Hymenoptera; also, the final 7-8 segments of the abdomen of an ant, just behind the petiole.
Generationa group of offspring from a parent population moving through a life cycle together.
Genus (plural, genera)a classification of insects with common characteristics; the main subdivision of a family; made up of a group of closely related species or of a single species.
Gummosisthe giving off of gummy substances as a result of cell degeneration.
Headthe anterior (front) most part of the three main body segments of insects which contains the antennae, eyes, mouth parts and brain.
Hibernaculum (plural, hibernacula)a case or covering for protection during the winter.
Honeydewthe liquid excrement of certain phloem-feeding insects, such as aphids, mealybugs, and pear psylla. It is composed of water, plant sugars and amino acids.
Hostan organism on or in which another (called a parasite) lives for nourishment or protection.
Induced pestan insect or mite raised to pest status by destruction of natural enemies.
Insectclass of Arthropoda that is characterized by three body divisions, three pairs of thoracic legs, and one pair of antennae.
Instara stage of an insect between molts; a growth stage.
Juvenile hormonehormone produced by the corpora allata and serves several functions including suppression of adult characters.
Key pestpest around which management programs are built. Examples are codling moth, oriental fruit moth and cherry fruit fly.
Lamella (plural, lamellae)a series of overlapping plate-like structures used to refer to the type of antennal club in some beetles.
Larva (plural, larvae)a comprehensive term for the immature stages of insects with complete metamorphosis (e.g.; flies, beetles, moths, wasps). Often specific names are given to the larvae of some orders or families fly larvae are called maggots, scarab beetle larvae are called grubs.
Lateralpertaining to the side of the body.
Life cyclethe sequence of events and stages that occurs in the life of an organism.
Life historythe sequence of events that occur during an annual cycle including the habitat setting where they occur
MesophyllThe soft green tissue inside a leaf between the lower and upper epidermis, chiefly concerned in photosynthesis.
Metamorphosisthe series of changes from the egg to the adult stage whereby insects grow and develop. Metamorphosis is said to be complete when the pupa is inactive or does not feed, and incomplete when the pupal stage is lacking, or is active and feeds.
Micronone thousandth of a millimeter, one millionth of a meter.
Minea hollow made by an insect under the surface of a leaf.
Moltthe process by which insects shed their outer skin (exoskeleton), in order to increase in size.
Morphologythe branch of biology that deals with the form and structure of animals and plants.
Myceliumthe vegetative part of a fungus, made of a mass or network of thread-like tubes.
Neurotoxina poison that interferes with nerve function.
Nympha comprehensive term for the immature stages of insects with incomplete metamorphosis (e.g.; true bugs, aphids, leafhoppers and grasshoppers).
Operculuma lid-like structure, usually over an egg.
Ovateshaped like the longitudinal section of an egg.
Ovicidean insecticide effective on the egg stage.
Ovipositoran organ of many female insects for depositing of eggs, often in a host.
Parasitean organism that lives on or in one of another species, from which it derives sustenance or protection. It usually does not benefit the host, and often does it harm. It may complete its life cycle without killing the host.
Parthenogenesisasexual reproduction by means of the development of an unfertilized egg. for example, in aphids a number of parthenogenetically produced generations succeed a sexually produced generation. Finally, males are produced (also by parthenogenesis) and sexual reproduction again occurs.
Pestan organism that interferes with human activities, property or health, or is objectionable.
Petiolein a plant, the stalk of a flower cluster or leaf; in an insect, the slender, stalk-like part between the thorax and abdomen of the body.
Phenologythe study of the effects of climate on recurring natural phenomena, such as insect or plant development.
Phenology modela model based on accumulated heat units used to predict significant events in the life cycle of a plant or insect (e.g.; full bloom, egg hatch).
Pheromonea chemical substance secreted by an insect to convey information to others of the same species.
Phyluma principal division of the animal kingdom.
Physiologyscience of the functions and phenomena of living organisms and their parts.
Phytophagousherbivorous, or plant-feeding.
Predatoran organism that lives by capturing and feeding upon another. Unlike parasitoids, predators consume many hosts during their development.
Prolegsthe stubby limbs on the abdomen of the larvae of Lepidoptera, sawflies and some other insects.
Prothoraxthe first segment of the thorax of insects, bearing the first pair of legs.
Protonymphsecond instar of an immature mite.
Pupastage between the larva and adult of an insect with complete metamorphosis.
Racea population that differs from others in the relative frequency of some gene or genes.
Recurrent veinsmall veins running transversely between major veins on the wings of Hymenoptera.
Refugium (plural, refugia)a small, isolated area that has escaped changes undergone by the surrounding area.
Scutelluma feature on the dorsum of an insect, made up of one or more of the thoracic segments a prominent feature of Hemiptera (true bugs), where it is a triangular-shaped part of the middle thoracic segment enclosing the angle of the forewings at rest.
Secondary pesta pest that is less important than a key or primary pest. Examples are aphids, mites and leafhoppers.
Selectiona process by which certain organisms or characters are favored or perpetuated in preference to others.
Seta (plural setae)a bristle or bristle-like part or organ.
Speciesthe basic unit of classification of living organisms. A class of similar insects that generally interbreed only among themselves; a subdivision of a genus.
Spermatophorea case or capsule containing a number of spermatozoa, expelled whole by the male of certain animals, including rust mites.
Spiraclea breathing pore; an external opening of the tracheal system.
Stagean insect’s developmental status (e.g.; egg stage).
Stipea usually short, thick stem such as found on certain mite eggs.
Stoma (plural, stomata)minute holes in leaves through which trees exchange gases.
Taxonomythe system of arranging animals and plants into natural, related groups based on some factor common to each. The basic taxonomic categories are, in descending order Kingdom, Phylum, Class, Order, Family, Genus, and species.
Thoracic shieldthe dorsal plate of the prothorax; a plate on the insect’s upper side just behind the head.
Thoraxthe middle of the three main divisions of the insect’s body; the body part between the head and abdomen that bears the legs and wings.
Tracheaa tube of the respiratory system that begins with a spiracle and ends with the tracheoles.
Tuberclea small, rounded projection.
Ventralunderside of the body.


The book, Orchard Pest Management, is copyrighted by the Washington State Fruit Commission. Permission is granted by the Commission to Washington State University to publish the book's content on the World Wide Web. Soft cover copies are available for purchase.


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