Insect Glossary

Glossary of Insect and Related Plant Terms and Order Characteristics


alates – winged forms of insects

anthocorids – a true bug in the family Anthocoridae

aphid – an insect in the family Aphidiidae which are sometimes called plant lice


bahiagrass – a type of lawn grass

beneficial insect – any insect that has a life style that is advantageous to man. Insects that preserve the balance of nature by feeding on others, pollinators, and recyclers are examples of beneficial insects.

Bermudagrass – a common grass which is used for lawns and forage


caterpillar – the immature stage of any Lepidoptera (butterflies and moths)

centipedegrass – a type of lawn (turf) grass

cephalothorax – head (ceph) and chest (thorax) area

cerci – paired appendages on the end of the abdomen of many insects which are used for sensing, defense or mating

chewing (mouth parts) – any mouth part that literally bites to feed; other mouth part types are sucking and rasping.
chlorosis – yellowing of a leaf

clavus – the enlarged terminal antennal segments that form a club

collophore – a tube-like structure on the underside of the first abdominal segment of Collembola (springtails)

compound eyes – the large multi-faceted eyes of insects

coreids – a member of the family Coreidae which are leaf footed bugs

corium – the elongate, thickened basal portion of the fore wing of Hemiptera

cornicles – tubular structure on each side of abdominal region from which pheromones or honeydew is expelled.

coxa (pl.=coxae) – basal portion of the leg

crepuscular – having activity periods during low light levels at dawn and evening

crown (of plant) – the center of a growing plant usually referring to a plant with a rosette

cursorial – adapted for running


dactyl – literally a finger or fingerlike projection on an insect body part

dealates – winged forms that have shed their wings, like reproductive termites or ants

defoliate, defoliation – removal of foliage from plants, often by chewing insects

detritivore – any organism that eats decaying organic matter

diapause – an insect resting stage, usually induced by environmental signals or extreme conditions like winter or summer

dimorphic – having two distinct forms


endosperm – a portion of a seed which contains most of the energy reserves for germination

estivation (aestivation) – a resting stage (quiescence) resulting from continued high temperature or xeric conditions; diapause; hibernation.

exoskeleton – the outer portion of an insect body which may be relatively soft like a caterpillar or hardened like many beetles

ESA – Entomological Society of America; the largest organization in the world serving the professional and scientific needs of entomologists and people in related disciplines. Founded in 1889, ESA today has more than 6,000 members. This number includes educators, extension personnel, consultants, students, researchers, and scientists from agricultural departments, health agencies, private industries, colleges and universities, and state and federal governments.


femora – a segment of an insect leg; usually the largest segment

filiform – linear shaped as the antennae of ground beetles

forage grass – any grass used for hay or animal grazing

forbs – any broadleaf non-woody (herbaceous) plant

frass – solid larval insect excrement; plant fragments made by wood-boring insects, usually mixed with excrement

furculum (plural: furcula) – the elongate fork-like appendage on the end of the abdomen (folds under the body) of Collembola (e.g. springtails) which is used as a spring action for leaping


genera – plural of genus; A genus is a group of plants or animals with similar characteristics. Animals (insects) are classified by kingdom, phylum, class, order, family, genus, species, author’s name. For example, the honey bee is classified as Animal (kingdom), Arthropoda (phylum), Insecta or Hexapoda (class), Hymenoptera (order), Apidae (family), Apis (genus), mellifera (species), Linnaeus (author’s name). The genus and species are always italicized.

girdle, girdling – damage of a plant that circles the stem or branch cutting off the connective plant tissue

gradual metamorphosis – See metamorphosis.

grigology – the study of crickets, grasshoppers and katydids


hemelytron – the first wing of a true bug (Hemiptera) which has the base more thickened than the membaneous outer portion

hopperburn – leaf damage caused by leafhopper feeding which is a yellowing of the leaves


imago – the adult stage of an insect

instar – an insect stage between molts; molting is growth.

internode – The part of a plant stem between the nodes. Nodes mark the point of attachment of leaves, flowers, fruits, buds and other stems.


Johnsongrass – a wild grass . It is the same species as the commercially ground varieties of sorghum.



larval stage (larva, larvae) – an immature insect, sometimes used to include all immature stages, even eggs. Usually this term refers more specifically to the feeding stages of insects with complete metamorphosis like grubs, caterpillars, and maggots.

legume – any plant which is a member of the pea family


maggot – in most Diptera (flies), legless larva lacking a distinct head, with cephalic (head) end pointed and caudal (rear) end blunt.

mesophyll – fleshy plant tissue inside a leaf or stem

metamorphosis – change in form during an insect’s growth and development.

  • gradual metamorphosis – incomplete metamorphosis in which there is no pupal stage and the immatures and adults look similar excluding the wings of the adults
  • incomplete metamorphosis – any metamorphosis type that does not include the pupal stage. Incomplete metamorphosis is present in Orthoptera (grasshoppers), Hemiptera (true bugs), and several other orders.
  • simple metamorphosis – any metamorphosis that occurs in insect groups that where they are not winged and have no pupal stage. Insect groups with simple metamorphosis include the Collembola (springtails) and Thysanura (silverfish).

metathorax – the second section of the insect thorax which houses the second pair of legs and the first pair of wings

mite – a member of the the order Acari (ticks and mites)

molt, molting process – in insects, as in snakes, the process of shedding the exoskeleton


naiad – a term for immature insects that are aquatic from the orders Plecoptera, Odonata, and Ephemeroptera. This term is becoming archaic and is now replaced by the more general term “immature” insect.

necrosis – death of tissue in plants or animals

nymphs – an immature stage of hemimetabolous insects (those with incomplete metamorphosis).


oothecae – a bean-like hardened egg capsule produced by female cockroaches

osmeterium (pl.=osmeteria) – scent-producing area behind the tibia

overwinter – time spent during the winter months. Insects are often in hibernation or at least rather immobile in the colder temperatures.

ovipositor – the egg laying apparatus of an insect. The stinger of a bee is actually a modified ovipositor.


parthenogenesis – egg development without fertilization

pedipalps – second pair of appendages of the cephalothorax corresponding to the mandibles of insects.

petiole – attachment of a leaf to stem

phloem and xylem – vascular tubes that allow fluid transport in plants. It is the way plants receive and distribute nutrients, hormones and water.

photosynthesis – the chemical process that plants use to convert carbon dioxide and water to sugars and ultimately to energy

phyto- (prefix) – plant

phytophagous – plant eating; an insect using plants as a food source

phytotoxemia – a toxic reaction in plants

Pierce’s disease (of grapes) – a bacterial disease of grapes transmitted by leafhoppers

poikilotherm – a cold-blooded organism

proboscis – a nose, or in the case of butterflies the coiled sucking mouthpart

pronotum – the plate on top of the prothorax

prothorax – the front part of an insect thorax which includes the attachment points for the front legs

protozoan – a microorganism in the kingdom Protozoa

pseudergates – caste found in the lower termites (Isoptera), comprised of individuals having regressed from nymphal stages by molts eliminating the wing buds, or being derived from larvae having undergone nondifferentiating molts, serving as the principle elements of the worker caste, but remaining capable of developing into other castes by further molting.

psocids – any insect in the order Psocoptera, which includes booklice and barklice

psyllid yellows – a virus disease of potatoes, tomatoes, peppers, and eggplant. See purple top.

pupal stage (pupa) – the stage in complete metamorphosis between larva and adult like the cocoon in moths

purple top – a purple discoloration of foliage tips caused by insect transmitted virus

pustulate – pus-forming, as in spider bites



Rhopalid – an insect in the family Rhopalidae in the order Hemiptera (true bugs).

rosetting – malformation of a plant resulting in a bunched irregular growth of the leaves


St. Augustinegrass – a warm weather turfgrass, common in Texas; medium water requirements, low shade tolerance (requires full sun), coarse leaf texture, mowing frequency every 5-7 days, high disease potential

scutellum – a triangular shaped section on the back of Hemiptera and some Coleoptera. It is often the identifying characteristic of Hemipterans or “true bugs”.

secondary reproductive – a caste of subterranean termite; also called supplemental reproductives; If these termites develop from nymphs, they are called secondary reproductives (primary reproductives are the king and queen). If they develop from pseudergates, they are called tertiary reproductives. Supplementals may be responsible for most of the egg productionin the colony.

soldier termite – See termite.
spinneret – a small tubular appendage from which silk threads by spiders and many larval insects

stippling (leaf) – a speckled appearance of a leaf, usually yellowish spots on a green leaf.

stolon – an underground portion of a plant that grows horizontally, like a grass root.

subgroup – a subset of a group with related characters. The term group is a general and non-specific collection of similar organisms regardless of taxonomic hierarchy.

subimago – the first winged stage of a mayfly. This is the only group to have a winged stage that molts. The final stage is the imago, or adult.


tarsi – a foot. Insect feet are made of several segments and may have pads, hairs, or hooks.

tegmina – plural of tegmen, a hardened covering like the forewing of many Orthoptera and Hemiptera

tenaculum – a minute two-pronged structure on the underside of the third abdominal segment of Collembola (springtails) which holds the furcula (appendage used for jumping) before it is released to jump
termite – any wood-eating insect in the order Isoptera

  • soldier termite – a caste of termites with specific structures to defend the colony, such as large mandibles or nasute mouths that produce sticky defensive substances.
  • worker termite – a caste of termites that do most of the work in the colony. Worker termites can be all immature termites and forms that do not develop into reproductive forms or soldiers.
  • tertiary reproductive termite – see secondary reproductive.

tettigoniid – a family of Orthoptera often called long-horned grasshoppers which includes katydids

thorax – the second body segment of an insect. The thorax has all of the wings and legs attached to it.

tip burn – a yellow or dried tip on a branch or leaf caused by insect feeding or a plant physiology disorder

true bugs – insects in the order Hemiptera. They are usually characterized by a scutellum, a triangular shaped section on the back.


understory – low growing trees and shrubs under a forest canopy. Any plant growing under a taller tree.


venation -the pattern of veins in the insect wing


wing pads – incomplete wing structures like those formed on immature grasshoppers




zoysiagrass – a variety of turfgrass; low water requirement, shade tolerant, cold tolerant, medium to fine leaf texture, low mowing frequency requirements (7-10 days), low disease potential.