Abdomen. The hindmost of the three main body divisions of an insect.

Allometric. Change of proportions with increase of size.

Ambrosia. The fungus cultivated by wood-boring beetles of the family Curculionidae subfamily Scolytinae.

Annulate. Formed in ring-like segments or with ring-like markings.

Antenna. (pl. antennae). Pair of segmented appendages located on the head and usually sensory in function - the 'feelers'.

Antennal cleaner. Comb-like structure for cleaning the antennae.

Antennal club. The more or less enlarged distal articles of a clubbed antenna.

Antennal fossa. Cavity in which antenna is located.

Antennal insertion. Area of attachment of antennae to head capsule.

Anterior. Concerning or facing the front, towards the head.

Anus. The posterior opening of the digestive tract.

Apex. The point where the costal vein and the outer margin of the forewing meet.

Apical. At or concerning the tip or furthest part of any organ: apical cells, for example are at the wing-tip.

Appendage. Any limb or other organ.

Appendiculate. Having a small appendage.

Aquatic. Living in water.

Arcuate. Curved or shaped like a bow.

Asymmetrical. Organs or body parts not alike on either side of a dividing line or plane.


Basal. Concerning the base of a structure - that part nearest the body.

Biflabellate. Condition where each side of antenna has flabellate processes.

Biological control. The control of pests by employing predators, parasites, or disease; the natural enemies are encouraged and disseminated by man.

Bioluminescent. Capable of light production.

Bipectinate. Feathery, with branches growing out on both sides of the main axis: applied mainly to antennae.


Campodeiform. (applied to a larva) Grub-like, flattened and elongated with well-developed legs and antennae.

Canaliculate. Canal-like

Canthus. The process more or less dividing eyes into an upper and lower part.

Capitate. With an apical knob like enlargement.

Carina. A ridge or keel.

Carnivorous. Preying or feeding on animals.

Cervical. Concerning the neck region, just behind the head.

Clypeus. Lowest part of the insect face, just above the labrum.

Comb. A group of spines on the leg of an insect specifically used for cleaning other parts of the insects body.

Compound eye. An eye consisting of many individual elements or ommatidia each of which is represented externally by a facet.

Contiguous. Touching.

Cordiform. Like a cord.

Costal margin. The front edge of the wing.

Costate. With one or more longitudinal ribs.

Crenulate. With scalloped margin.

Cupule. Cup-shaped structure.

Cuticle. The outer noncellular layers of the insect integument secreted by the epidermis.


Dentate. Toothed, possessing teeth or teeth-like structures.

Denticulate. Bearing very small tooth-like projections.

Detritivore. Feeding on detritus.

Discrimen. A median longitudinal sulcus of the pterothorax, marking an invagination of the sternum.

Dorsal. On or concerning the back or top of an animal.

Dorso-ventral. Running from the dorsal (upper) to the ventral (lower) surface.

Dorsum. The upper surface or back of an animal.


Ectoparasite. A parasite that lives on the outside of its host.

Elbowed Antenna. Antenna, in which there is a distinct angle between two of the segments - usually between the 1st and 2nd segments, in which case the 1st segment is usually much longer than the others.

Elytral humeri. Basal exterior angles of elytra.

Elytron. (plural elytra) The tough, horny forewing of a beetle.

Emarginate. With a distinct notch or indentation in the margin.

Empodium. A spine or lobe-like process of the ventral sclerite between the claws.

Epimeron. The posterior part of the side wall of any of the three thoracic segments.

Epipleuron (pl. epipleura). The deflexed or inflexed portion of the elytron, laterally when elytra are closed.

Exarate Pupa. A pupa in which all the appendages, legs etc., are free and capable of movement.

Excavate. Hollowed out: applied to the coxae of many beetles, which are hollowed out to receive the femora when the legs are folded.

Explanate. Having a flat extension.


Facetted. With facets, the outer cuticular elements of light receptive elements of the compound eye.

Femur. The 3rd (counting out from the body) and often the largest segment of the insect leg.

Filiform. Thread-like, applied especially to antennae.

Flabellate. With projecting flaps on one side, applied especially to antennae.

Flagellum. The distal (furthest away from the body) part of the antenna, beyond the 2nd segment.

Fossorial. Adapted for digging.

Frons. Upper part of the insect face, between and below the antennae.

Frontoclypeal suture. The suture between the frons and the clypeus.

Fusiform. Tapering gradually at both ends: spindle-shaped.


Galea. the outer branch of the maxillae, the inner one being the lacinia.

Gena. The cheek - that part of the head below and behind the eye.

Geniculate. Abruptly bent or elbowed (see Elbowed Antenna).

Glabrous. Without setae.

Granulate. Appearing as if made up of granules.

Gula. Ventral part of the head capsule.


Head. The anterior body region of insects which bears the mouthparts, eyes, and antennae.

Holoptic. With the eyes touching or almost touching on the top of the head.

Humeral Angle. The front basal part of the wing, close to its attachment to the body.

Hydrofuge. Water repelling.

Hypognathous. Having a vertical head and face with the mouth-parts at the bottom.

Hypomeron. Inflexed portion of the pronotum, beneath the lateral margin.


Interfacetal. Between the facets of the compound eye.

Interstriae. Between the striae of the elytron.


Joint. Strictly speaking, an articulation between neighbouring parts, such as the femur and tibia of the leg, but the word is commonly used as a synonym of segment - meaning any of the divisions of the body or its appendages.


Labial palp. Segmented appendage on labium.

Labium. The 'lower lip' of the insect mouth-parts, formed by the fusion of two maxilla-like appendages.

Lamellate. Possessing thin plates.

Larva (pl. larvae). Immature stage of insect that has a complete metamorphosis.

Lentic. Still water.

Ligula. Collective name for the inner and outer pair of lobes, fused or not, on the labium.

Lotic. Running water.


Mandible. The jaw of an insect.

Mandibulate. Having mandibles suited for biting and chewing.

Maxilla. (plural maxillae) One of the two components of the insect mouth-parts lying just behind the jaws.

Maxillary palp. Segmented appendage on maxilla.

Maxillary. Concerning or to do with the maxillae.

Membranous. Thin and transparent.

Mentum. Basal sclerite of labium.

Mesepimeron. Posterior division of the lateral sclerite of the mesothoracic segment.

Mesepisternum. Anterior division of the lateral sclerite of the mesothoracic segment.

Mesonotum. Dorsal sclerite on the mesothoracic segment.

Mesoscutum. Shield-shaped second, or middle part of the mesonotum.

Mesosternum. The ventral surface or sclerite of the mesothorax.

Mesothorax. Second or middle thoracic segment.

Metasternum. Ventral sclerite of the metathoracic segment.

Metathorax. Third or posterior thoracic segment.

Metepisternum. Anterior division of the lateral sclerite of the metathoracic segment.

Moniliform. (of antennae) Composed of bead-like segments, each well separated from the next.

Moniliform. Arranged like a chain of beads.

Mycanguim (pl. mycangia). A special pocket-shaped receptacle used to carry symbiotic fungi.


Nearctic. Northern hemisphere of the New World.

Notopleural suture. Suture separating the pronotum and the proepisternum.

Notosternal suture. Suture separating the prosternum for propleuron.


Ocellus. (Plural Ocelli) One of the simple eyes of insects, usually occurring on the top of the head.


Palp. A segmented leg-like structure arising on the maxilla or labium. Palps have a sensory function and play a major role in tasting food.

Pectinate. Having branches which arise from the main axis like the teeth of a comb: usually applied to antennae.

Pedicel. The 2nd antennal segment.

Perforate. Having pores.

Pheromone. A substance secreted by an animal which when released externally in small amounts causes a specific reaction, such as stimulation to mate with or supply food to a receiving individual of the same species.

Phytophagous. Feeding upon plants.

Plastron. In aquatic insects, a film of air on the outside of the body, providing an extensive air-water interface for gaseous exchange.

Predator. An animal that attacks and feeds on other animals, usually smaller and weaker than itself.

Proepisternum. Anterior division of the lateral sclerite of the prothoracic segment.

Prognathous. Having a more or less horizontal head, with the mouth-parts at the front.

Proleg. One of the fleshy, stumpy legs on larvae.

Pronotum. The dorsal surface or sclerite of the 1st thoracic segment.

Propleuron (pl. propleura). Lateral region of the prothoracic segment.

Prosternum. Ventral surface of the 1st thoracic segment.

Prothorax. First or anterior thoracic segment.

Pubescent. Covered with short, soft setae.

Punctate. Covered with tiny pits or depressions.

Pupa. (pl., pupae). The 3rd stage in the life history of beetles and other insects undergoing a complete metamorphosis during which the larval body is rebuilt into that of the adult insect; a non-feeding and usually inactive stage.

Pygidium. The abdominal terga left exposed by the elytra.


Quadrate. Square or rectangular.


Radial cell. A wing cell bordered anteriorly by a branch of the radial vein.

Radial vein. The first important longitudinal vein in the wing, behind the costal margin.

Reticulate. Covered with a network pattern.

Rostrum. Elongated snouts of weevils.

Rugose. With many wrinkles or ridge.


Scale. A flattened seta.

Scape. The 1st antennal segment, especially if it is longer than the other segment.

Sclerite. Any of the individual hardened plates which make up the exoskeleton.

Sclerotization. The hardening and darkening processes in the cuticle (involves the epicuticle and exocuticle with a substance called sclerotin).

Securiform. Having the form of an axe or hatchet.

Segment. One of the rings or divisions of the body, or one of the sections of a jointed limb.

Serrate. Toothed like a saw.

Seta. (pl., setae). A bristle or hair-like process of the integument.

Spatulate. Spoon-shaped.

Spine. A multicellular, thorn like process or outgrowth of the integument not separated from it by a joint.

Spinose. Spiny.

Spiracle. One of the breathing pores - openings of the tracheal system - through which diffusion of gases takes place. They usually occur on the third thoracic segment and all the abdominal.

Spur. A large and usually movable spine, normally found on the legs.

Sternopleural suture. Suture separating sternum form pleural sclerite.

Sternum. The plate or sclerite on the underside of a body segment.

Striae. Grooves running across or along the body: applied especially to the grooves on beetle elytra.

Striate. With parallel, fine, longitudinal, impressed lines or furrow.

Stridulation. The production of sounds by rubbing two parts of the body together.

Stridulatory file. The file of sound producing scleletal elements.

Strigulate. With numerous short and fine transverse line, either raised or impressed.

Striole. A rudimentary stria.

Sub-apical. Situated just before the tip or apex.

Subcosta. Usually the first of the longitudinal veins behind the front edge of the wing, although it is often missing or very faint: abbreviated to Sc.

Subcostal. Anterior submargined part of wing.

Subgena. Narrow lateral margin of the head capsule below the gena.

Submoniliform. Somewhat similar to a chain of beads.

Subserrate. With small teeth or notches.

Supraorbital. Situated above the eye.

Suture margin. Line of juncture of elytra.

Suture. A groove on the body surface which usually divides one plate or sclerite from the next: also the junction between the elytra of a beetle.


Tarsus. (pl., tarsi). The insect's foot: primitively a single segment but consisting of several segments in most living insects.

Temple. Part of head capsule above and behind eyes.

Tergum. The dorsal surface of any body segment.

Testaceous. Brownish-yellow.

Thorax. The middle of the three major divisions of the insect body. The legs and wings (if present) are always attached to the thorax.

Tibia. (pl., tibiae) The fourth leg segment between the femur and the tarsus.

Tomentose. Covered with tomentum.

Tomentum. A form of pubescence composed of short, matted, woolly setae.

Trochanter. The second segment of the leg, between coxa and femur: often very small and easily overlooked.

Trochantin. Free sclerite located at base of leg, providing moveable point of articulation for coxa.

Truncate. Ending abruptly: squared off.

Tubercle. A small knob like or rounded protuberance.


Uncus. A hook-like process on the distal inner margin of the maxillary lobe.

Urogomph(s). In larval Coleoptera, usually paired processes from the posterior end of the tergum of the ninth abdominal segment, either jointed and movable by muscles, or unjointed and unmovable.


Vertex. The top of the head, between and behind the eyes.


Xylomycetophagous. Cultivation and utilization of a symbiotic fungus as a food source.

Xylophagous. Wood consumers.