San Diego Natural History Museum--Your Nature ConnectionSDNHM Field Guide

Glossary of Entomology Terms

ABC | DEF | GHIJ | KLM | NOPQ | RST | UVWXYZ

Abdomen
One of an insect's three main body segments on which spiracles and reproductive organs are located; the most posterior segment.
Adaptation
Physical structures, characteristics or behaviors that allow an organism to survive and reproduce in its particular environment.
Annual
A plant that lives one year only.
Antennae
Sensory organs located on an insect's head used mostly for smell and hearing.
Anterior
Referring to the front end of an insect or animal.
Calamistrum
Row of toothed bristles on the metatarsal segment of the last leg, used to comb out cribellate silk.
Carapace
A hard covering over the dorsal surface of the body, or of at least the thorax.
Cephalothorax
First subdivision of a spider's body, combining the head and thorax.
Chelicerae
The first pair of appendages below the cephalothorax of a spider.
Chitin
Substance produced by an insect which hardens and forms its exoskeleton.
Chrysalis
The pupa, or stage of a butterfly's life cycle between larva and adult.
Cocoon
The silken case spun by many moth larvae as a protection for their pupae.
Compound Eye
Eye composed of many units, each with a lens or facet.
Cremaster
The hook-like process on the end of a chrysalis that attaches the pupa to the stem, twig, etc.
Cribellum
Sievelike spinning plate in front of the spinnerets.
Diurnal
Active during the day.
Diversity
Presence of a wide range of body types and systems in a taxon.
Dorsal
Referring to the upperside of an animal, the "back" side.
Entomology
The study of insects.
Exoskeleton
Supporting structure on the outside of the body of insects and other invertebrates.
Frass
The solid waste droppings of a larva or caterpillar.
Habitat
The kind of place where a plant or animal naturally lives.
Head
One of three main segments of an insect's body on which eyes, mouth, and antennae are found; the most anterior segment.
Holotype
The specimen of an animal (or plant) which is designated in the publication when the organism is named, as representing what is meant by the new name. The holotype specimen may or may not be the first ever collected, and may or may not be a good example of its kind, but it is the official designation: "THIS name refers to THIS animal." Often, other specimens are cited in the same publication, and are called "secondary types."
Instar
The period between two molts.
Larva (pl., larvae)
The immature stage in metamorphosis between the egg and pupa (plural: larvae). Butterfly larvae are referred to as caterpillars.
Lateral
Referring to the sides of the body.
Lepidoptera
"Scaley wing"-the order, or classification group, to which butterflies and moths belong.
Mandible
Mouthpart (jaw) on the head of the larva and some adult insects.
Medial
Referring to the mid-line of the body.
Metamorphosis
The process by which an animal changes in size and form during development.
Metatarsus (pl., metatarsi)
Sixth of eight segments of a spider's leg between the tibia and the tarsus; insects do not have this leg part.
Molting
Process of shedding old exoskeleton to make way for new.
Nectar
The sweet liquid produced by plants which some insects drink.
Nocturnal
Active at night.
Palp (pl., palpi)
Sensory structure on the head used like a tongue.
Pedipalps
Second pair of appendates on the cephalothorax of a spider, used to guide prey to the mouth.
Perennial
A plant that blossoms annually; continuous; undying.
Pesticides
Chemicals used to poison insects or other pests.
Posterior
Referring to the tail end.
Proboscis
Structure like a drinking straw used to suck up nectar or other fluids.
Prolegs
"False" legs on abdominal segments of larva.
Scale
Shingle-like covering on the membrane of the wing that gives butterflies and moths their colorful patterns.
Spinneret
Organ on the bottom of the larva head used to spin silk; in spiders.
Spiracles
Holes along the side of an insect's body through which it breathes.
Tarsi
Plural form of tarsus; last or distal leg segment consisting of one to five subdivisions or segments.
Tentacles
Sensory organs found at the front and rear of the Monarch larva, also called filaments.
Thorax
The second body segment of an insect, between the head and abdomen, on which wings and legs are located.
Tibia
Fourth leg segment, just preceding the tarsus.
Type specimen
A specimen which is designated in the publication of a new name for an organism.
True legs
Appendages located on the thoracic segments of a larva.
Variation
Individual differences found within a species, for example, differences in size, shape, color, presence or absence of certain structures.
Ventral
Referring to the underside of an animal, the "tummy" side.
Vein
A thin, mostly hollow structure in the wing.