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Biological Control : A Guide to Natural Enemies in North America Anthony Shelton, Ph.D., Professor of Entomology, Cornell University



Abdomen: The last of the three major body divisions of an insect.

Action threshold: The pest density at which a control tactic must be implemented to avoid an economic loss.

Active ingredient (AI): The component of a pesticide formulation responsible for the toxic effect.

Agroecosystem: A relatively artificial ecosystem in an agricultural field, pasture, or orchard.

Antenna, Antennae (pl.): A pair of sensory organs located on the head of an insect, above the mouthparts.

Aorta: The front-most, non-pulsating portion of the dorsal blood vessel of an insect.

Arthropod: Any of the invertebrate animals (such as insects, spiders, or crustaceans) having an exoskeleton, a segmented body and jointed limbs.

Augmentation: Biological control practices intended to increase the number or effectiveness of existing natural enemies.

Bacterium: A single-celled microscopic plant-like organism that does not produce chlorophyll.

Beak: Colloquial expression for the protruding mouthpart structures of a sucking insect (= proboscis).

Biological control: The use of living organisms, such as predators, parasitoids, and pathogens, to control pest insects, weeds, or diseases. Typically involves some human activity.

Biorational: Having a minimal disruptive influence upon the environment and its inhabitants (e.g., a biorational insecticide). Broad-spectrum (insecticide): Active against a wide range of insects.

Bt: The bacterium, Bacillus thuringiensis.

Caterpillar: The immature stage (larva) of a butterfly, moth, or sawfly.

Chemical control: Pest management practices which rely upon the application of synthetic or naturally-derived pesticides.

Class: A category of the classification scheme of living organisms ranking below a phylum and above an order (e.g., Insecta).

Classical biological control: The importation of foreign natural enemies to control previously introduced, or native, pests.

Cocoon: A silken case formed by an insect larva for pupation.

Cole crops: Crops such as cabbage, broccoli, Brussels sprouts, and other crucifers.

Complete metamorphosis: Type of insect development characterized by four distinct stages: egg, larva, pupa, and adult.

Conservation: Any biological control practice designed to protect and maintain populations of existing natural enemies.

Contact poison: A pesticide that is absorbed through the body wall, as opposed to one that must be ingested.

Cucurbits: Vine crops such as cucumbers, melons, squash, and pumpkins.

Cultural control: Pest management practices that rely upon manipulation of the cropping environment (e.g., cultivation of weeds harboring insect pests).

Density (insect populations): The number of insects per unit of measure (e.g., beetles per square meter).

Diapause: A physiological state of arrested metabolism, growth, and development that occurs at a particular stage in the life cycle of an organism.

Dormancy: A recurring period in the life cycle of an organism when growth, development, and reproduction are suppressed.

Ecology: The study of an organism's interrelationship with its environment.

Economic threshold: see Action threshold.

Elytra: The thickened or leathery front or forewings of insects such as beetles.

Encapsulation: The surrounding of an invading body, such as the egg of a parasite, by insect hemocytes (blood cells) and the formation of a protective capsule.

Entomopathogenic: Insect-attacking organism.

Environmental impact quotient (EIQ): A relative value that estimates the environmental impact of a pesticide, by taking into account toxicity to natural enemies, wildlife, and humans, degree of exposure, aquatic and terrestrial effects, soil chemistry, etc.

Epizootic: A disease outbreak within an insect population.

Exoskeleton: A skeleton or supportive structure on the outside of an insect body.

Exotic: Introduced from another country or continent (e.g., introduced insect pest).

Family: A taxonomic subdivision of an order, containing a group of related genera. Family names end in -idae.

Forewing: The first or anterior pair of insect wings.

Fumigant: A substance which produces a gas, vapor, fume, or smoke intended to kill a pest.

Fungicide: Any substance that kills or inhibits the growth of a fungus.

Funicle: The portion of the flagellum of the antenna closest to the club.

Fungus, Fungi (pl.): Any of numerous plants lacking chlorophyll, ranging in form from a single cell to a body of branched filaments. Includes the yeasts, molds, smuts, and mushrooms.

Gene: A biochemical unit of hereditary, often coding for an entire protein.

Generalist: A pest or natural enemy that can utilize a wide range of species as host or prey.

Generation: Period from any given stage in the life cycle to the same life stage in the offspring. Typically from egg to egg.

Genetic engineering: The manipulation of the genetic material of an organism in order to achieve desirable characteristics.

Genus, Genera (pl.): A group of evolutionarily related species, sharing one or a number of characteristics.

Gradual metamorphosis: A type of insect development in which there is no prolonged resting stage (pupa). The three stages are: egg, nymph, and adult.

GV: Granulosis virus.

Habitat manipulation: Manipulation of agricultural areas and surrounding environment with the aim of conserving or augmenting populations of natural enemies (e.g., the planting of a refuge for natural enemies).

Head: The anterior region of an insect, which bears the mouthparts, eyes, antennae and houses the brain.

Herbicide: A substance used to kill or control weeds.

Hermaphroditic: Having both male and female sex organs in one individual.

Hindwings: The second pair of wings of an insect.

Honeydew: The sugary liquid discharge from the anus of certain insects (Homoptera) such as aphids and scales.

Host: The organism in or on which a parasitoid lives; a plant on which an insect feeds.

Host plant resistance: The relative amount of heritable qualities possessed by a plant that reduces the degree of damage to the plant by a pest or pests.

Hyperparasite: A parasite whose host is another parasite.

Indigenous: Native to an area.

Inoculative release: The release of relatively small numbers of natural enemies that are expected to colonize, reproduce, and spread naturally throughout an area.

Insect growth regulator (IGR): A substance, natural or synthetic, that controls or modifies insect growth processes.

Insecticide resistance: Genetically inherited ability to withstand doses of pesticide which would kill individuals from strains whose ancestors had not been exposed to the pesticide.

Insect resistant (plants): Tolerant of, or resistant to, insect attack (as in plants). individuals from strains whose ancestors had not been exposed to the pesticide.

Instar: The stage of an insect's life between successive molts, for example the first instar is between hatching from the egg and the first molt.

Integrated pest management (IPM): An approach to the management of pests in which all available control options, including physical, chemical, and biological controls, are evaluated and integrated into a unified program.

Integument: The outer covering of the insect body that includes the cuticle and the epidermis.

Introduction (classical biological control): The importation of a natural enemy from a foreign country or continent, usually to control a pest also of foreign origin.

Inundative release: The release of relatively large numbers of natural enemies to suppress pest populations, without the expectation that the natural enemies will colonize and spread throughout the area.

Larva, Larvae (pl.): The immature stage between the egg and pupa of insects having complete metamorphosis where the immature differs radically from the adult (e.g., caterpillars, grubs).

Leafy greens: Lettuces and other leaf vegetables.

Least toxic: Having a minimal toxic effect upon non-target organisms.

Life Cycle: The sequence of events that occurs during the lifetime of an individual organism.

Maggot: The immature form (larva) of a fly or wasp, lacking legs and a well-developed head.

Mass-reared: Produced in large numbers, as in natural enemies produced for release programs.

Mechanical control: Control of pests by physical means such as the use of screens or row covers.

Metabolism, Metabolic: Chemical changes that occur in living cells to provide energy for vital activities and to assimilate new material.

Metamorphosis: A change in body form during development of an insect.

Microbial: A microscopic organism; a germ.

Microbial insecticide: A preparation of microorganisms (e.g., viruses or bacteria) or their products used to suppress insect pest populations.

Microsporidia: Single-celled life forms, related to Protozoa.

Mite: Any of several minute invertebrates belonging to the phylum Arthropoda, class Arachnida.

Morphology: Form or structure of an organism.

Multivoltine: Having more than one brood or generation per season.

Mycelium, Mycelia (pl.): A mass of interwoven filamentous 'threads' that make up the vegetative part of a fungus.

Native (insect or plant): Of local origin, not intentionally or accidentally introduced.

Natural control: The suppression of pest populations by naturally occurring biological and environmental agents.

Natural enemies: Living organisms found in nature that kill, weaken, or reduce the reproductive potential of other organisms.

Nectar: The sugary liquid secreted by many flowers.

Nematode: An elongated, cylindrical worm parasitic in animals, insects, or plants, or free-living in soil or water.

NPV: Nuclear polyhedrosis virus.

Nymph: The immature stage, following hatching from the egg, of an insect that does not have a pupal stage.

Ocelli: Simple eyes on some adult and larval insects. Typically there are three, which form an inverted triangle dorsally, the function of which is obscure.

Order: A taxonomic subdivision that contains groups of related families or superfamilies; usually ending in -ptera in insects.

Overwinter: A period of rest or hibernation by which insects survive the winter.

Oviposition: The laying or depositing of eggs.

Ovipositor: The egg-laying apparatus of a female insect.

Palp (palpus): Sensory organ attached to insect mouthparts that is used to test the quality of food.

Parasite: An organism that lives in or on another organism (the host) during some portion of its life cycle.

Parasitoid: An animal that feeds in or on another living animal, consuming all or most of its tissues and eventually killing it.

Parthenogenesis: Development of an insect, from egg to adult, without fertilization.

Pathogen: A disease-causing organism.

Pest: An organism that interferes with human activities, property, or health, or is objectionable.

Pest management: see Integrated pest management.

Pesticide: A substance that is used to kill, debilitate, or repel a pest.

Pest-resistant crops: Crops that possess attributes which minimize damage by pests.

Phenology: The seasonal life history of an insect population.

Pheromone: A substance, such as a sex attractant, that is given off by one individual and causes a specific reaction in other individuals of the same species.

Phylum, Phyla (pl.): One of the major divisions of the animal kingdom.

Physical Control: Control of pests by physical means such as heat, cold, sound waves, etc.

Polyembryonic (eggs): A single egg that divides to form two or more (often hundreds) identical embryos.

Polyembryony: Having several embryos.

Population: A group of individuals of the same species within a given space and time.

Predaceous: Preying upon other organisms, predatory.

Predator: An animal that attacks and feeds on other animals, normally killing several individuals during its life cycle.

Pronotum: The upper, often shield-like, hardened body-wall plate, located just behind the head of an insect.

Protozoan: A microscopic, single-celled organism that is largely aquatic and includes many parasitic forms.

Pupa, Pupae (pl.): The nonfeeding stage between the larva and adult in insects with complete metamorphosis.

Puparium, Puparia (pl.): A case formed by the hardening of the last larval skin, in which the pupa is formed; usually of flies.

Pupate: To transform to a pupa.

Resistance (insecticide or pesticide): see Insecticide resistance.

Resistance (plant): see Host plant resistance.

Resurgence (pest): The development of large populations of pests that had previously been suppressed.

Sampling: Estimating the density of organisms (pests or natural enemies) or damage by examining a defined portion of the crop.

Scouting, Scout: see Sampling.

Septicemia: Blood poisoning caused by pathogenic organisms.

Specialist: A pest or natural enemy that utilizes a narrow range of species for its host or prey.

Species: A group of individuals similar in structure and capable of interbreeding and producing fertile offspring. They are different in structure from other such groups and do not interbreed with them.

Spiracles: The external openings of the insect breathing (tracheal) system, found along the abdomen.

Spore: A reproductive structure developing in certain bacteria and fungi which is strongly resistant to environmental influences but which will become active under suitable conditions.

Stage (life stage): A distinct period in the development of an organism (e.g., for some insects, egg, larval, pupal, and adult stages).

Stomach poison: An insecticide that is lethal only after it has been ingested by an insect, entering the insect body through the gut.

Systemic insecticide: An insecticide that is absorbed into plant sap and is lethal to insects feeding on or within the treated plant.

Thorax: The insect body region behind the head which bears the legs and wings.

Tolerance (host-plant resistance): The ability of a plant to withstand injury by pests.

Transformed (Bt-transformed): Transfer and expression of a gene (e.g., for Bt toxin) into another organism.

Trap crop: A small area of a crop used to divert pests from a larger area of the same or another crop. The pests, once diverted to the trap crop, may be treated with an insecticide.

Univoltine: Having only one brood or generation per season.

Vector: An organism capable of carrying and transmitting a disease-causing agent from one host to another.

Virus: Any of various submicroscopic pathogens which can only replicate inside a living cell.

Taken from:

Hoffmann, M.P. and Frodsham, A.C. (1993) Natural Enemies of Vegetable Insect Pests. Cooperative Extension, Cornell University, Ithaca, NY. 63 pp.

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A mosquito larva infected by Lagenidium giganteum

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