Insects and their Allies  
Glossary of Terms
Abdomen: the rear section of the three major body divisions, located at the end of the thorax.
Aestivate: to pass the summer in a dormant or torpid state.
Book lung: respiratory organ in many arachnids consisting of many thin folds of membrane resembling the leaves of a book.
Calcareous: consisting of or containing calcium carbonate, calcium, or limestone.
Canada balsam: a resin-based substance used for mounting specimens onto microslides for viewing under a microscope. See also Euparal.
Carnivores: animals that feed on the flesh of other animals.
Carnoy's: a substance consisting of glacial acetic acid, 95% ethyl alcohol and chloroform which is used for fixing large larvae of moths, butterflies, beetles, bees and wasps as it preserves their colour and body marking and prevents shrinkage. The larvae must be placed alive in the fixative. For more information refer to Upton (1991).
Caste: a distinct type of body form within a colony of social insects e.g. soldier, worker, queen.
Caterpillar: a soft bodied larva with a number of prolegs or false legs on the abdomen in addition to the six true thoracic legs. Usually refers to the larvae of moths and butterflies.
Cellulose: the substance which makes up the essential parts of tissues and fibres in plants, wood, linen and paper.
Cephalothorax: the front body section of arachnids and some crustaceans which consists of the fused head and thorax.
Cerci: a pair of jointed appendages on the tip of the abdomen of insects and other arthropods.
Chelicerae: the first pair of fang-like appendages near the mouth of an arachnid, often modified for grasping and piercing.
Cocoon: a protective case often of silk or similar fibrous material forming a natural protective covering or structure around such things as the pupae or eggs of some invertebrates.
Complete Life Cycle: the growth cycle where the young have a different form from the adults and undergo a pupal stage to become the adult. Stages usually consist of egg-larvae-pupa-adult.
Compound eyes: eye which consists of many light-sensitive lens, each with its own refractive system and each forming a portion of an image.
Cribellum: a sieve-like organ of some spiders which is used for spinning a special kind of silk.

Cuticle: hardened or membranous protective layer covering the body of many invertebrates especially arthropods.
Elytra: the hardened forewings used to protect the membranous hind wings of insects in the order Coleoptera (beetles and weevils).
Entognathous: having the mouthparts in pockets or oral folds from which they can be protruded when feeding.
Ethyl alcohol: distilled alcohol made from grain and often used in medicines, colognes, cleaning solutions and rocket fuel .
Euparal: a resin-based substance used for mounting specimens onto microslides for viewing under a microscope. See also Canada balsam.
Femur: (pl: femora) the third of five segments of an insects' leg and is often the largest segment.
Filamentous: (filiform) thin and thread-like.
Furca: any fork-like structure; esp. in reference to the fork-like 'tails' of Collembola.
Glycerol: a syrupy, sweet, colourless or yellowish liquid obtained from fats and oils and often used in cosmetics, liquid soaps, inks, and lubricants or as a sweetener or antifreeze.
Halteres: small club-shaped structures that vibrate and act as gyroscopic stabilisers. They are the reduced hind wings of insects in the Diptera order.
Heinz (PVA) mounting medium: a substance made with poly vinyl alcohol, distilled water, glycerol, phenol/distilled water solution, chloral hydrate and lactic acid used as a temporary mounting medium. This medium tends to degrade over time but is useful is specimens do not need to be kept. Specimens can be lifted from slides by dissolving the mountant in lactophenol.
Herbivores: animals that feed on plants.
Hermaphrodite: an animal or plant; having both male female reproductive organs.
Hexapod: six legged
Hoyers: a water-miscible substance made up of gum arabic, chloral hydrate, water and glycerine used as a mounting medium for specimens on microslides.
Incomplete Metamorphosis: where the young develop gradually, appearing similar to the adults and do not undergo a pupal stage.
Instar: refers to one stage of growth between moults, e.g. 3 larval instars (or growth stages) before an insects pupates. The number of larval instars varies between insects and may range from 3 to 30.
Isopropyl alcohol: is a clear, colourless liquid with a bitter taste and a smell of acetone. Often used in rubbing alcohol, household cleaning products and antifreeze.
KAA: a substance consisting of glacial acetic acid, 95% ethyl alcohol and kerosene which is used for fixing large larvae of moths, butterflies, beetles, bees and wasps as it preserves their colour and body marking and prevents shrinkage. The larvae must be placed alive in the fixative. For more information refer to Upton (1991).
Larva: (larvae) the immature stage of most insects. Usually grub-like in appearance.
Mandibles: the jaws of an insect which consist of the upper chewing pair of mouthparts, sometimes modified into other shapes.
Mandibulate: biting or chewing mouthparts.
Membranous: transparent, usually referring to the flying wings of insects.
Mesonotum: the upper surface covering the middle segment of the thorax of insects.
Metamorphosis: a change in the appearance or function of a living organism, by a natural process of growth or development.
Monofiliform: of bead-like appearance, usually in reference to the shape of antennae.
Moult: to shed the hard outer skin of an invertebrate during growth.
Nocturnal: being most active during the night.
Nymph: the immature stage of certain species of insects. Nymphs usually resemble their parents but are mostly smaller and lack wings.
Ocellus: (pl: ocelli) simple eye consisting of a single lens. Simple eyes often occur in patterns of three in many insects.
Omnivore: an animal that feeds on both animal and vegetable matter.
Ootheca: an egg case of some insects and molluscs which is formed by the hardened of a sticky substance secreted from a special organ known as the colleterial gland.
Ovipositor: tubular apparatus, usually concealed but sometimes extending some length outside the end of the abdomen, with which many female insects deposit eggs.
Parasite: (vrb: parasitise) an organism that feeds on or in a different organism while contributing nothing to the survival of its host.
Parasitoid: a term which is applied to insects whose larvae are parasites of other insects and eventually kill the host.
Pedipalps: one of the second pair of jointed appendages near to the mouth arachnids that are modified for reproductive, predatory, or sensory functions.
Pheromone: a chemical secreted by an animal, especially insects that influences the behaviour of other animals of the same species. Often used as an attractant for the opposite sex.
Phloem: the food-conducting tissue of vascular plants.
Plumose: having feathers or feather-like growths or resembling a plume.
Predators: an organism that exists by preying on other living organisms.
Preorally: before or in front of the mouth.
Prepupa: an inactive stage just before the pupal stage in the development of some insects.
Proboscis: the lengthened mouthparts which are modified to form a tube for piercing and sucking, or other specialised ways of feeding. This term may also refer to the coiled feeding tube of moths and butterflies. See rostrum also.
Prolegs: small, short leg-like appendages on the abdomen of some caterpillars that assist in locomotion.
Pronotum: the upper surface of the first segment of the thorax of an insect. May be enlarged to form a shield over the rest of the thorax.
Pupa: (pl: pupae) a non-feeding and relatively inactive stage between the larvae and adults stages of insects with a complete life cycle. Often referred to as a chrysalis in butterflies and moths.
Pupating: (pupate) to go through the pupal stage. See Pupa.
Radula: a flexible tongue-like organ in some molluscs that consists of rows of horny teeth on the surface.
Raptorial: adapted for catching and holding prey. They usually have sharp claws and spines or bristles.
Rostrum: the elongated piercing and sucking mouthparts of all species in the Hemiptera. Also applied to the snout of weevils (Curculionidae). See proboscis also.
Scape: the first and usually the largest segment of the antennae.
Scavengers: an animal that feeds on dead or decaying material.
Sclerotised: hardened or toughened tissue, like the elytra of a beetles forewing.
Spermatophore: a packet or capsule containing spermatozoa which is produced by the male to be transferred to the female for fertilisation.
Spinnerets: tubular structures found on the end of the abdomen of spiders and some insect larvae (e.g. silkworms) that secrete silk threads from which they form webs or cocoons.
Symbiotic: a relationship between two or more different organisms of different species that does not necessarily benefit each member.
Tarsus: (pl: tarsi) the last of the five sections of an insects' leg, i.e. "the foot". The tarsus itself is also divided into five parts.
Thorax: the middle section of the three major body divisions, located between the head and the abdomen. The wings and legs are all appendages of the thorax.
Tibia: the forth of five segments of an insects' leg, usually the longest segment and is often thin, straight or slightly curved and may have spines.
Uropods: one of the last pair of appendages on the end of the abdomen of certain crustaceans, such as the lobster or slater.
Xylem: the supporting tissues and water-conducting tissue of vascular plants.