Glossary of entomology terms

A–C

abdomen

Body of the insect, toward the posterior of the thorax.

acaricide

A chemical employed to kill and control mites and ticks.

acariphagous

feeding on mites (also refers to parasitoids of mites).

accessory gland

Any secondary gland of the glandular system.

accessory pulsatile organs (APOs)

Small muscular pumps and the veins that accompany them that pump hemolymph into the wings.

acetyl choline

Alternative spelling of "acetylcholine".

acrostichal bristles

The two rows of hairs or bristles lying one on either side of the mid-line of the thorax of a true fly.

active space

The space within which the concentration of a pheromone or other behaviorally active substance is concentrated enough to generate the required response, remembering that like light and sound pheromones become more dilute the further they radiate out from their source.

aculeate

(Hymenoptera) Any member of a group of families that include the familiar stinging ants, bees, and social and hunting wasp.

acuminate

Tapering to a long point.

acylurea

A class of insect growth regulators.

adeagus

The part of the male genitalia which is inserted into the female during copulation and which carries the sperm into the female. Its shape is often important in separating closely related species.

adecticous

Of pupa: the state in which the pupa does not possess movable mandibles, the opposite being decticous.

adipocytes

A major cell type of insects that stores fat body and reserves nutrients.

admarginal

(adjective): Along the margin.

aedeagus

The sclerotized terminal portion of the male genital tract that is inserted into the female during insemination.

aestivation

Summer dormancy, entered into when conditions are unfavourable for active life i.e. it is too hot or too dry.

age polyethism

The regular changing of roles of colony members as they get older.

air sac

A dilated portion of a trachea.

alar squama

The middle of three flap-like outgrowths at the base of the wing in various flies.

alary muscles

muscles along the dorsal diaphragm that may perform circulation.

alata

the parthenogenetic winged morph of vividae, specialized for migration.

alate

Winged; having wings.

aldrin

(common name). A synthetic insecticide; a chlorinated hydrocarbon of not less than 95 per cent 1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-1,4:5,8-dimethanonaphthalene; moderately toxic to mammals, acute oral LD,, for rats 44 mg/kg; phytotoxicity: none when properly formulated, but some crops are sensitive to solvents in certain formulations.

algophagy

feeding on algae.

aliphatic

A term applied to the "open chain" or fatty series of hydrocarbons.

alitrunk

Name given to the thorax and propodeum of 'wasp-waisted' hymenopterans.

alloparental

When individuals other than the parent assist in the caring for that parents offspring.

allopatric

Two or more forms of a species having essentially separate distributions.

alternating generations

When two generations are produced within a life cycle each producing individuals of only one sex, either male first and then female or vice versa.

altruistic

Self-destructive. or potentially self-destructive behavior performed for the benefit of others.

alula

a broad lobe at the proximal posterior margin of the wing stalk of Diptera.Also termed the axillary lobe.

ambrosia

The fungus cultivated by wood-boring beetles of the family Scolytidae.

ametabola

The insects which develop without metamorphosis, namely the Protura, Thysanura, and Collembola.

amide

Compound derived from carboxylic acids by replacing the hydroxyl of the -COOH by the amino group, -NH₂-.

amine

An organic compound containing nitrogen, derived from ammonia, NH₃, by replacing one or more hydrogen atoms by as many hydrocarbon radicals.

amino acid

Organic compounds that contain the amino (NH₂) group and the carboxyl (COOH) group. Amino acids are the "building stones" of proteins.

ammonia

A colorless alkaline gas, NH₃, soluble in water.

anal

Pertaining to last abdominal segment which bears the anus.

anal angle

The posterior corner of the wing (same as tornus).

anal fold

A fold in the inner margin of the hindwing.

anal valves

Exposed claspers at the end of the abdomen.

anaplasmosis

Infection with Anaplasma, a genus of Sporozoa that infests red blood cells.

anasa wilt

A wilt disease of cucurbits caused solely by the feeding of the squash bug, no parasitic microorganism involved.

androconia

(singula = Androconium) In male butterflies, specialised wing scales (often called scent scales) possessing special glands which produce a chemical attractive to females.

androconium or androconia (plural)

Specialised microscopic scales on the wings of male butterflies, believed to be scent scales for attracting the female.

annulate

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

anemic

Deficient in blood quantity or quality.

anteclypeus

the lower (anterior) portion of the clypeus of insects.

antennae

The long feelers situated on the head and close to the eyes. They are however not tactile but used for detecting airborne scents and currents.

In Papilionoidea the antennae end in bulging tips called clubs.

In Hesperioidea they have hooked tips and the club is found just before the tip.

In some Lycaenidae like the genus Liphyra the antenna tapers gradually.

antennation

Touching with the antenna.

antenniferous

Bearing antennae, as in "antenniferous tubercle".

antennomere

A segment of an antenna. The term antennomere is used in particular when the segments are fairly uniform, as in filiform antennae, but it also may be used in referring to segments of odd sizes, shapes and functions, such as the scape and pedicel. More specific terms may be used where there are distinct antennal regions; for example flagellomeres are the antennomeres comprising the flagellum.

anterior

in front of or after the aforementioned structure.

antenodal veins

Small cross-veins at the front of the dragonfly or damselfly wing, between the wing base and the nodus.

anthophagy

feeding on flowers.

antibiosis

An association between two or more organisms that is detrimental to one or more of them.

anticoagulin

A substance antagonistic to the coagulation of blood.

anus

The posterior opening of the digestive tract.

apex / apical area

The anterior corner of the wing.

apical cell

The first posterior cell in the wing of Diptera.It is the space between the third and fourth longitudinal vein beyond the anterior crossvein (R5).

aphidophagy

feeding on aphids (and parasitoids of aphids).

apitherapy

Medicinal use of the honey bee or its products.

arculus

A crossvein between the radius and cubitus near the base of the wing in certain insects.

areola

A small ring of color

arolium

A pad-like median lobe between the tarsal claws.

base / basal area of wing

Region close to the point of attachment to the thorax.

brand

Raised area on the wing surface, circular, ovate, or elongated, which is covered with special scent scales or androconia, found in males of some species. Also called sex mark.

bryophagy

feeding on moss.

capitate

Mainly referring to antennae, but occasionally to other anatomical features such as palps: having a clubbed shape with a relatively long, slender stem, but with an abruptly bulkier, thicker, possibly globular distal head, the capitulum. The term capitate is not strictly distinguished from clavate, but where a distinction is desired, it is that the club of a capitate antenna is abruptly distinct from the shaft, and the head tends to be short and more or less globular. The club of a clavate antenna generally is a more or less tapered thickening, sometimes hardly distinct from the shaft.

capitulum

The head of a capitate structure, such as a capitate antenna, or of a capitate haltere

carina

a keel-like elevation (or ridge) on the body-wall of an insect.

carpophagy

feeding on fruits and seeds.

catenulate

Markings consisting of rings connected together like a chain.

cell

The central area surrounded by veins. It can be closed by veins or open.

The vein forming the boundary of the cell along the costal margin is known as the subcostal vein q.v.

The vein forming the lower boundary towards the dorsum is called the median vein.

In the case of butterflies, the cell is closed by a vein connecting the origins of veins 6 to 4 along the top of the cell which is known as discocellular vein.

cell cup

Taxonomically important term used in Diptera identification keys. Part of the schema of wing venation. Also called the posterior cubital cell and often called the anal cell. see File:Phytomyzinae wing veins-1.svg

ceratophagy (Also spelled keratophagy)

feeding on cornified tissues and hair of animals.

cervix

(Anatomical feature) the structure defining the neck of the insect.

chaeta

See Seta.

chalaza

An external spine that has a single point. Etymology: Greek chalasa, a tubercle. cf. scolus, which has multiple points.

cheta

See Seta.

cilia

Fine hairs along the edges of the wing.

clasper or clasp

A structure in male insects that is used to hold the female during copulation.

clava

Same as clavus.

clavate

Mainly referring to antennae, but occasionally to other anatomical features such as palps: having a clubbed shape with a relatively long, slender stem, but with a bulkier, thicker distal end, the clava. The term clavate is not strictly distinguished from capitate, but in general, where a distinction is desired, the club of a capitate antenna is abruptly distinct, even globular, whereas the club of a clavate antennae is generally a more or less tapered thickening

claviform stigma

specifically, in Noctuidae (moths)- an elongate spot or mark extending from the anterior transverse anterior line through the submedian interspace, toward and sometimes to the posterior transverse line.

clavola

Same as clavus or club

clavus

1.  The thicker distal end of a clavate anatomical structure such as an antenna. Usually comprising more than one joint. Also called clava, clavola, or club2.  The posterior of the portion of the remigium found on insect wings.3.  The oblong sclerite at the base of the inferior margin of the hemelytron in Heteroptera.4.  The knob at the end of the stigmal or radial veins in the wings of certain Hymenoptera.

club

The popular (possibly to be preferred) name for the clavus of a clavate antenna.

clypeus

(Anatomical feature) a sclerite structure below the frons, circumposed by the mandibles and above the labrum.

coccidophagy

feeding on scale insects (and parasitoids of scale insects).

compound eye

An eye consisting of a large number of individual photoreceptor units or ommatidia (ommatidium, singular).Figure 2 d below

connexivum or connexiva (plural)

(largely in Heteroptera and similarly dorsoventrally flattened insects) the edge of the abdomen, containing the connection between the tergite and sternite. May be visible from above in species such as many of the Reduviidae.

copromycetophagy

inhabiting feces and consuming mycetes growing inside or cultivating them for feeding.

coprophagy

feeding on the excrements of animals.

costa / costal area

The leading edge of the wing.

costal break

Taxonomically important term used in Diptera identification keys. Part of the schema of wing venation. weakenings of the costa (one to three in number). They are flexing points for the wings during flight

coronal suture

(Anatomical feature) an anterior suture line of the head between the compound eyes, below the median ocellus.

coxa

first leg segment, between body and trochanter.

cremaster

A general term for a structure by which an object hangs (from Greek language kremastos, meaning "hung up"); for example in entomology:
in some Lepidoptera, including most butterflies, the pupa attaches to a surface by the cremaster, a structure at the tip of the pupal abdomen. The cremaster is the homologue of the anal plate of the caterpillar. It takes various forms in different species, ranging from a simple point, to various arrangements of hooks that catch Velcro-like in a silken pad that the caterpillar spins on the surface before it enters the prepupal phase.

crenulate

Adjective = scalloped. Describes the outer edge of a wing that is convex at the end of each vein and concave in between.

cuneus

Noun = wedge. Particularly in mirid bugs, a wedge-shaped section of the hemelytra (forewings), located at the apex of the thick, leathery part of the wings.

D–F

decticous

Functional mandibles present in pupal state.

dendrophagy

feeding on trees.

dentate

As for crenulate but with the projections at the end of each wing being toothlike.

detritophagy

feeding on ground remains of plants and animals.

disc / discal area

The central band passing through the cell.

discoidal cell

In damselflies (Zygoptera) a basal quadrangular cell in the wing venation, which is delimited by veins MA (anterior side), MP (posterior side), MAb (distal side) and the arculus (basal side).

dorsum / dorsal area

The trailing edge or hind-margin of the wing, extending from the base to the tornus. Dorsal alternately, also refers to the back, i.e. the upper part of the body, from above.

ectognathous

(Anatomical feature) having exterior mouthparts, or exposed. A defining feature of insects.

emarginate

(Anatomical feature) Describing a margin, such as the edge of an eye or sclerite, where the outline includes a concave section as if a part of the region had been "cut out" or displaced. It might take the form of a notch, or a rounded or possibly quadrate hollow, such as where a compound eye is distorted in fitting around the base of the antenna.

empodium

(Anatomical feature) either a bristle-like or pad-like structure between the tarsal claws of various insects, notably Diptera.

encapsulation

the immuno response by plasmatocytes to the presence of parasitoid egg or larvae which results in the formation of a multilayered capsule that causes the parasitoid to sufficate or starve.

entomonecrophagy

feeding on dead arthropods.

entomophagy

feeding on other insects.

epicranius

(Anatomical feature) the top of the anterior structure of the head, or forehead.

epiproct

(Anatomical feature) a plate or projection dorsal to the anus in certain insects, generally on abdominal segment X or XI. For example in Archaeognatha and Zygentoma it takes the form of a long, rearwardly directed organ resembling the two cerci that flank it. In the Odonata epiprocts have various functions, both in larvae, in which they may have respiratory roles, and in adults, in which they may have reproductive roles. Not all epiprocts in all insect species are homologous. Note that the term is used in other groups than insects as well, for instance Myriapoda.

erect

The palpi when vertical, i.e. the axis of the palpi is at right angles to the axis of the body.

exarate

Pupae with their legs and other appendages free and extended.

eyespots

1.  Spots or other patterns resembling vertebrate eyes on the skin, such as on larvae of some Sphingidae or the wings of moths such as many Saturniidae. Such eyespots have no visual function, but act variously to misdirect or discourage attacks from predators.2.  Simple eyes such as ocelli or stemmata

face

the area between the base of antennae, oral margin, eyes and cheeks (gena). See figure 3.

fascia (plural fasciae)

A color pattern with a broad band.

femur

third leg segment, between trochanter and tibia.

flagellomere

an antennomere comprising part of the flagellum.

flagellum

the part of the antenna distal to the pedicel composed of one or more segments, called flagellomeres.

foramen magnum

(Anatomical feature) the posterior opening of the head capsule, covered by the cervix.

forewing

(Anatomical feature) the pair of wings of a four-winged insect closest to the head.

frons

(Anatomical feature) The frontal area of an insect's head. It covers the upper part of the face above the clypeus and below and between the antennae. It supports the pharyngeal dilator muscles and usually bears an ocellus.

frontal sutures

(Anatomical feature) suture lines that meet with the coroanl sutures to form an inverted Y.

G–L

gena

(Anatomical feature) the area below the compound eyes, the insect equivalent to human cheeks.

geniculate

Elbowed. From the Latin for a bended knee, referring to an organ of a type not always expected to be kinked, but having a definite angular bend or hinge. In entomology the term typically refers to an elbowed antenna. For instance, many species of Hemiptera, Coleoptera, and Hymenoptera have markedly geniculate antennae

girdle

a strand of silk used to prop up the pupa. Found especially in the Papilionidae.

glabrous

smooth, without hairs or scales.

gula

ventral head sclerite which supports the submentum

helminthophagy

feeding on worms classified with helminths (including parasitoids of helminths).

hemocoel

the interior of the insects anatomy, including all organs and hemocyte.

hemocyte or haemolymph

a fluid in the circulatory system of insects containing nutrients, fat, water, etc.

hemophagy

feeding on blood.

hindwing

(Anatomical feature) the pair of wings of a four-winged insect farthest from the head.

hyaline

transparent, like glass.

hygropetric

mode of life: living in the thin film of water on wet rocks.

hypognathous

having mouthparts that are ventrad of a vertically oriented head, or having an "under bit".

hypopharynx

Mouthpart. A tonguelike lobe on the floor of the mouth.

idiobiont

a form of parasitism where the parasitoid paralyzes or leaves the host unable to continue development at oviposition.

imago

(plural is usually imagines) The final, or adult, stage in metamorphosis.

interspace

The region between adjacent veins.

irrorated or irroration

Old term used usually to indicate a sprinkling of scales interspersed among scales typically of a different color.

keratophagy (Also spelt ceratophagy)

feeding on cornified tissues and hair of animals.

koinobiont

A form of parasitism where the parasitoid lives inside the host while allowing it to live after oviposition.

labium

Mouthpart forming the lower lip. Bears the labial palps.

labrum

(Anatomical feature) the anterior structure below the clypeus covering some of the mouthparts, sometimes called the "upper lip".

lichenophagy

feeding on lichens.

lines of weakness

(Anatomical feature) the suture lines where the integument will split to allow for molting.

lunule

A body area or marking roughly in the shape of a crescent.

M–O

macrochaete

large bristles and scales.

macropterous

Having long or large elytra, as long, or longer than the abdomen.

malacophagy

feeding on mollusks (and parasitoids of mollusks).

maxilla

Mouthpart. The maxillae are paired and arranged behind the mandibles. May bear palps. See Figures 1 and 3.

membranule

a small triangular opaque region at the base of the hindwing in some dragonflies.

mesothorax

the middle segment of the thorax, between the prothorax and the metathorax.

metalmarks

small metallic-looking spots commonly found on the wings of Riodinidae.

metathorax

The third and last segment of the thorax after the mesothorax.

micropterous

Having short elytra, shorter than the abdomen.

mixomycetophagy

feeding on myxomycetes fungus.

myiasis

Infestation of fly larvae on or in a vertebrate host.

mycetophagy

feeding on fungus.

necrophagy

consuming of dead animals and their remains.

nervure

Older term for vein. adnervural refers to instance lines running adjacent and alongside the veins.

nodus

(of Odonata ) A prominent cross-vein near the center of the leading edge of a wing.

obtect

Appendages fused or glued to the body.

occipital suture

(Anatomical feature) the structure that defines the occiput. See Figure 1 (below).

occiput (insect)

(Anatomical feature) the region posterior to the vertex on the head. See Figure 2 (below).

ocular structure

(Anatomical feature) the structure of the head containing the ocelli.

onisciform

A woodlouse shaped, flattened platyform appearance of a larva.

oophagy

feeding on eggs.

opisthognathous

with receding mouthparts, or having mouthparts that slope backward or face backward.

orbicular stigma

a marking placed between the reniform stigma and the thorax, usually circular in shape.

osmeterium

fleshy structure on some larvae, often discharging odorous chemicals.

oviposition

the act of laying eggs.

oviscape

if part of the ovipositor is visible when not in action, then the basal visible portion, typically tubular, is the oviscape. For examples, see females of many Tephritidae and Pyrgotidae (cf scape).

ovipositor

structure by which many insects place their eggs, sometimes by piercing or slitting the host or substrate in which she lays the eggs. The structure may be tubular and may have valves.

ozadene

a stink gland or repugnatorial gland, from which an animal such as an insect or Myriapod may release a foul-smelling liquid or gas for defence

ozopore

the opening of an ozadene, a stink gland or repugnatorial gland

P–R

palynophagy

feeding on pollen.

parasitoid

In parasitism, the participant that benefits, rather than the one that is being parasitized.

pedicel

the second segment ( antennomere) of the antenna. See figure 3.

pedipalp (or labial palpi or palpi)

Comparatively large processes that originate from below the head and curve forward in front of the face that sometimes appear like a beak. lp on the figure right.

phloeophagy

feeding on bark.

phyllophagy

feeding on leaves.

phytophagy

feeding on plants.

pleurite

A sclerotised region on the lateral part of an insect segment, bearing the spiracle, and separating and connecting the tergite and the sternite (compare: pulmonarium).

pollinophagy

feeding on pollen.

porrect

The palpi when horizontally projecting in front of the face. In this case, the axis of the palpi is parallel to the axis of the body.

postclypeus

the upper (proximal) portion of the clypeus of insects.

posterior

in a position behind or below the aforementioned.

postoccipital suture

(Anatomical feature) the structure posterior to the occipital suture, surrounding foramen magnum or occipital magnum.

proboscis

tubular feeding and sucking organ.

proclinate

Directed or leaning forward, such as in bristles in particular locations of insects' heads.

prognathous

having mouth parts dorsad of a dorsally oriented head, or "over bite".

proleg

fleshy leg like structures arising from the abdominal segments of caterpillars. These prolegs have crochets or curved hooks.

prothorax

The first segment on the thorax anterior to the mesothorax.

pterostigma (plural pterostigmata)

The prominent cell, usually opaque and coloured, near the tip of each wing of the Odonata, on the anterior margin; also, more loosely, called stigma.

pterothorax

The meso- and metathorax of winged insects, that carries the two pairs of wings.

pulmonarium (plural pulmonaria)

A membranous instead of a sclerotised connection or pleurite between the abdominal tergites and sternites of certain groups of insects; in such species the pulmonaria bear the spiracles. The term also refers to an abdomen in which the connection between the tergal and sternal sclerites takes the form of a pulmonarial membrane. (Compare: pleurite)

reniform stigma

an oval or kidney-shaped mark on the forewing at the disc (Lepidoptera)

repugnatorial

(generally in combination as in: "repugnatorial glands"): defensive, or "fighting back", in particular as applied to an ozadene, a gland that can release irritant, poisonous, alarming or distasteful fluids or gases when an organism is under threat. Examples of repugnatorial glands include the osmeterium of larvae of the Papilionidae, the stink glands of most Heteroptera, the ozadenes of Opiliones, the odoriferous glands of Diplopoda, and others.

rhizophagy

feeding on rhizomes.

S–Z

saltatorial

adapted for leaping or jumping.

sarconecrophagy

feeding on dead bodies of vertebrates.

sapromycetophagy

inhabiting decaying matter and consuming mycetes growing inside or cultivating them for feeding.

saprophagy

feeding on decaying organic matter.

scape

the proximal segment ( antennomere) of the antenna. See Figure 3.

schisophagy

feeding on ground remains of plants and animals.

scolus

An external spine having multiple points. Etymology: Greek skolos, a prickle. cf. chalaza. plural: scoli

sensu

Latin term meaning "in the sense of".

sequestering

The process of animals accumulating poisonous compounds from the food they are eating in order to become poisonous themselves for their predators. Pyrrolizidine alkaloid sequestration refers to the sequestration of one such class of poisonous compounds.

seta

A stiff chitinous or sclerotised hair or bristle. Also chaeta, cheta

setaceous

being like or having the nature of a seta or of setae

setose

setose

bearing, or covered in setae.

setula

Diminutive of seta. A small chitinous hair or bristle.

setulose

bearing, or covered in setulae.

spiracle

Respiratory openings on the thorax and abdomen that allow air to enter the trachea.

sporophagy

feeding on mycet spores.

stigma (plural stigmata)

Prominent cells on the forewings of some moths. Their size, shape and colour can be useful in identifying some species. Also the prominent cell, usually opaque and coloured, near the tip of each wing of the Odonata, on the anterior margin; also called pterostigma.

strigae

Patterns with thin lines.

subcosta

Taxonomically important term used in Diptera identification keys. Part of the schema of wing venation.The second longitudinal wing vein, posterior to the costa. It may reach the costa, fade before the costa or join R1 before it reaches the costa. see [2] (= auxiliary vein of many authors)

subgenal suture

(Anatomical feature) suture lines below the gena.

symplesiomorphy

a shared ancestral ("primitive") character state that cannot be used to demonstrate the monophyly of a group.

synapomorphy

a shared homologous and derived character state (evolutionary novelty) that demonstrates the monophyly of a group (clade).

synovigenic

a form of reproduction in which the female continues to produce and to mature eggs throughout its life cycle.

tarsus (plural tarsi)

fifth (last) leg segment, the part that touches the walking surface.

termen

The edge of the wing most distant from the body.

terminal and marginal

Along the margin.

thorax

The part of the body that lies between the head and the abdomen. It has three parts - prothorax, mesothorax and metathorax.

tibia

fourth leg segment, between femur and tarsus.

tomentum

a pubescence consisting of soft, entangled hairs pressed close to the surface of the integument.

tornus / tornal area

The posterior corner of the wing.

trochanter

second leg segment, between coxa and femur.

trophi

The mouthparts of Arthropoda such as insects; typically labrum, mandible, maxilla, labium.

trophus

The singular form of trophi (rarely used).

uncate

hook-like, as in the mouthparts of many fly larvae. (also uncinate)

uncinate

hook-like, as in the mouthparts of many fly larvae. (also uncate)

unguis (plural ungues)

pretarsus the claws at the tip of most insect pretarsi.

urite

a segment or part of the abdomen in insects.

urotergite

plate on the dorsal (upper) surface of an abdominal segment in insects.

valve

One of several appendages that combine to form the ovipositor of a typical female insect.

valvifer

In female Heteroptera valvifers comprise four blades, one pair on each of abdominal segments 8 and 9. They articulate with the paratergites and bear their corresponding valvulae.

valvula

One of four blades in a female Hemipteran with a laciniate type of ovipositor, that combine to form the ovipositing mechanism.

vein

Hollow structures formed from the coupling of the upper and lower walls of the wing. They provide both rigidity and flexibility to the wing. (See also Comstock-Needham system.)

vertex

(Anatomical feature) The apex of the head, usually containing ocelli.

villose

covered with numerous thick-set, slender projections resembling short hairs.

xylomycetophagy

inhabiting wood and consuming mycetes growing in wood or cultivating them for feeding.

xylophagy

feeding on wood.

zoomycetophagy

feeding on fungus found on other animals.

zoophagy

feeding on animals, and/or animal matter.