Glossary of Entomological Terms

These are presented as aid in understanding many of entomological terms you may encounter in the literature or in class exercises. New terms will be added as needed. Please feel free to suggest changes, additions, improvements. You may send your comments directly to me at
Applies to:
abdomen The posterior and usually longest of the 3 principal body segments General
allotype Paratype of the opposite sex to the holotype; term not regulated by Code of Zoological Nomenclature, (glossary, PDF format) Classification
anal lobe Lobe in the posterior basal part of wing Wing
anal vein Longitudinal unbranched veins extending from base of wing to outer margin below the cubitus Wing
antenna Pair of segmented appendages located on the head above mouthparts, below and between eyes; plural = antennae Head
antenodal crossvein Small cross veins along the basal portion of the front edge of wings Odonata
anterior In front; before General
arculus Small crossvein near base of wing Odonata
arista Large bristle, usually dorsally located, on apical antennal segment Diptera
aristate Last segment enlarged and bearing a conspicuous dorsal bristle Antennal forms
arolium A cushion-like pad on the tarsi of many insects, one of the lobes of the pulvillus General
arolium The terminal pad between the claws Orthoptera
auct., auctorum Of authors Latin Abbreviations
author The person(s) to whom a work, a scientific name, or a nomenclatural act is attributed Classification
basitarsus Basal (1st) segment of tarsus; segment connecting to tibia Leg
beak The jointed structure or rostrum covering the maxilla or trophi Hemiptera
binomen The combination of two names, the first being the generic name and the second a specific name, that together constitute the scientific name of a species Classification
binomial nomenclature The system of nomenclature in which a species, but no taxon or any other rank, is denoted by a combination of two names Classification
book gills Respiratory apparatus consisting of leaflike folds Xiphosura (Horseshoe crab)
c., circa About, near Latin Abbreviations
calypter One or two small lobes at base of wing, just above haltere Diptera
caudal Refers to tip of abdomen, toward the tail, posterior end of body General
cenchrus Pl. cenchri; minute, often white marks or membranous spaces on the metanotum Hymenoptera
cercus Segmented paired appendages located at tip of abdomen (plural = cerci) General
cf., cfr., Compare Latin Abbreviations
character Any attribute of organisms used for recognizing, differentiating or classifying taxa Classification
cladistic classification Classification based on 'recency of common descent', i.e.Categories depend on the position of the branching points on the inferred phylogenetic tree Classification
classification The ordering of organisms into groups on the basis of their relationships Classification
clavate Clublike, enlarged at tip (e.g clavate antennae). General
clavus Oblong or triangular anal portion of front wing Hemiptera, Homoptera
claw A hollow, sharp organ, generally paired, at the end of the insect leg General
clubbed Segments increasing in diameter distally Antennal forms
clubbed - (capitate) Terminal segments abruptly enlarged to form a club Antennal forms
clubbed - (clavate) Gradual increase in diameter of segments Antennal forms
clubbed - (lamellate) Terminal segments expanded laterally to form rounded or oval platelike lobes Antennal forms
clypeus Plate on face above mouthparts, between labrum and frons Head
collophore Tubelike sturcture located on ventral side of 1st abdominal segment Collembola
compound eye Composed of many elements or ommatidia General
corbicula A concave, smooth space, edged by a fringe of hairs arising from the margins of the posterior tibia in bees, forming pollen basket Hymenoptera
corium Elongate, usually thickened, basal portion of front wing Hemiptera
cornicle Tubelike structure located dorsally on abdomen Homoptera, Aphids
costa Longitudinal wing vein, usually enlarged and along the leading (anterior) edge of the wing Wing
coxa Basal segment of leg (plural = coxae) Leg
cubitus vein The 5th longitudinal vein of the wing, extending from wing base and usually 2-branched before reaching outer wing margin Wing
cuneus Small triangular area at end of embolium of hemelytra Hemiptera
definition A statement in words that purports to give those characters which, in combination, uniquely distinguish a taxon Classification
description A more or less complete statement of the observed characters of a taxon, without any special emphasis on thosewhich distinguish it from other closely related taxa Classification
diagnosis A statement in words that purports to give those characters which differentiate the taxon from other taxa with which it is likely to be confused Classification
diagnostic characters The characters, or most important characters, which distinguish a taxon from other similar or closely related taxa Classification
distal Near or toward the free end of any appendage; that part of segment farthest from the body General
dorsum Top surface of body General
elytron Thickened front pair of wings Coleoptera, Dermaptera, Hemiptera
embolium Narrow sclerite extending along anterior margin of hemelytra, from base to cuneus or membrane Hemiptera
embolium Narrow piece of corium, along costal margin Hemiptera
empodium Padlike or bristlelike structure at tip of last tarsal segment between claws Diptera
epi- Prefix, above General
epimeron Area of thoracic pleuron posterior to pleural suture General
epiphysis A lappet-like process covering an excavation on the foretibia Lepidoptera
epiproct Supra-anal plate; pygidium General
epistomal sulcus The frontoclypeal furrow Head
f., forma Form, shape Latin Abbreviations
family group The highest-ranking group of taxa whose names are fully regulated by the Code. The family group includes taxa at the ranks of superfamily, family, tribe, and any other rank below superfamily and above the genus group that may be required, such as subtribe Classification
femur Large leg segment located near base of leg; the 3rd leg segment,located between trochanter and tibia Leg
filiform Threadlike, segments nearly uniform in diameter, elongate, usually cylindrical Antennal forms
filiform Threadlike, hairlike (see also antennae) General
flagellomere Segment of flagellum General
flagellum Distal segments of antenna after pedicel Antenna
fontanelle Small, depressed pale spot on front of head between eyes Isoptera
frenulum Bristle or group of bristles at humeral angle of hind wing Lepidoptera
frons Front of head between epistomal suture and frontal sutures, includes median ocellus Head
furcula Forked springing apparatus Collembola
gen. nov., g.n., genus novum New genus Latin Abbreviations
gena Lateral portion of head below and behind eyes, the "cheek" Head
geniculate Elbowed; first segment long, following segments smaller, going off at an angle from the first Antennal forms
genitalia Collectively, all of the genital structures General
haltere, halter Modified wing; usually a small knobbed structure on 3rd thoracic segment (Diptera) or modified front wing in Strepsiptera Diptera, Strepsiptera
head Most anterior body region; with eyes, antennae, mouthparts General
hemelytron Front pair of wings in Hemiptera, usually with a thickened basal region Hemiptera
holotype A single specimen designated or indicated the type specimen by the original author at the time of publication of the original description Classification
homonym Each of two or more identical but independently proposed names for the same or different taxa Classification
humeral angle Basal anterior angle of or portion of the wing General
humerus Shoulder, anterior lateral angle of elytra Coleoptera
hypognathous With head and mouthparts located ventrally when viewed from above Head
hypopleuron Plate on thorax above hind coxae Diptera
hypostoma Portion of the head included between the antennae, eyes and mouth Diptera
id., idem The same Latin Abbreviations
identification The placing of individual specimens into previously established taxa, by deductive procedures. The determination of the taxonomic identity of an individual Classification
in litt., in letteris In correspondence or letter Latin Abbreviations
in litteris, in litt. In correspondence, communicated in writing, used for an unpublished source acknowledgement Classification
in litteris, in litt. In correspondence, communicated in writing, used for an unpublished source acknowledgement Latin Abbreviations
jugum Sclerite of the head Hemiptera, Homoptera
jugum Lobelike process at base of front wing, overlaps hind wing Lepidoptera
labial Referring to labium, mouthpart similar to lower lip of vertebrates Head
labium Mouthpart, lower lip Head
labrum Upper lip, below clypeus Head
lamellate Containing some enlarged, flattened segments General
lateral Relating, pertaining, or attached to the side General
lectotype One of several syntypes, designated by any author, after the original publication of a species name as the 'type specimen' for the taxonomic name. Designated only where there was no original holotype Classification
loc. cit., loco citato Work cited (includes page references) Latin Abbreviations
loco citato, loc. cit. In the place cited, used to avoid repetition of a bibliographic reference already given Classification
mandible Jaw, anterior pair of mouthparts Head
maxilla Paired mouthparts posterior to mandibles Head
media vein Fourth of the longitudinal veins, extending from base through approx. middle of wing, not more than 4-branched Wing
medial Referring to, or at the middle General
mesonotum Dorsal portion of second thoracic segment; location of 1st pair of wings Thorax
mesopleuron Lateral plate of mesonotum (dorsal region of second thoracic segment) Thorax
metanotum Third segment of thorax; contains 2nd pair of wings General
moniliform Like a string of beads Antennal forms
moniliform Beadlike, with rounded segment (see also antennae) General
monotypy A situation where a genus group taxon is established with only one immediately subordinate taxon. E.g. A genus containing only one species Classification
mystax A patch of hair or bristles above the mouth, on the lower part of the hypostoma above the vibrissae Diptera
n.g., nov. gen., novum genus New genus Latin Abbreviations
n.s., n.sp., nova species New species Latin Abbreviations
nasutiform Head narrowing anteriorly into a snout-like projection Isoptera
neotype A specimen selected as type specimen subsequent to the original description in cases where the original holotype, or lectotype, or all paratypes, or all syntypes are lost or destroyed or suppressed by the Commission Classification
nodus Strong cross vein near middle of costal border of wing Odonata
nomenclature The description of new taxa or alterations to the concept of previously described taxa which involve changes in the names of taxa Classification
notopleuron Area on thoracic dorsum, at lateral end of transverse suture Diptera
numerical taxonomy Study of the relationships of taxa by the application of numerical similarity values to characters so as to rank into categories based on degree of overall similarity Classification
occiput That part of the head behind the vertex Head
ocellus A simple eye of insects or other arthropods; appearing to be small raised spots on top of head Head
op. cit., op. c., opere citato Work cited (not page reference) Latin Abbreviations
palp Small segmented appendages associated with mouthparts (maxillae or labium) Head
paralectotype Any of the original syntypes remaining after the selection of a lectotype Classification
paraproct A pair of lobes bordering the anus laterally General
parapsidae Small sclerites on each side of the scutellum in Chalcids Hymenoptera
parapsidal furrows Longitudinal grooves on each side of the mesoscutum of Proctytrypiae separating the parapsides from the middle lobe Hymenoptera
parapsidal grooves Grooves or furrows on each side of the Chalcid scutellum Hymenoptera
parapsides Lateral pieces of meso-scutum, separated from mesal portion by parapsidal furrows Hymenoptera
parapteron Small sclerites, articulated to the dorsal extremity of the episternum, just below the wings; absent on thorax; = tegulae in Hymenoptera, patagia in Lepidoptera General
paratype Every specimen in a type series other than the holotype which were before the author at the time of preparation of the original description and were so designated and indicated there Classification
pectinate Comblike; most segments with long, slender processes Antennal forms
pectinate With branches like the teeth of a comb (see also antennae, claws) General
pedicel Second antennal segment Antenna
pedicel Greatly narrowed or restricted apparent 1st abdominal segment which connects the propodeum with the gaster Hymenoptera
pedicel Stem of the abdomen, between thorax and gaster (ants) Hymenoptera
pedunculated Set on a stalk or peduncle; attached by a slender stalk or neck General
petiole Stalk or stemlike constriction of the abdomen to form attachment to thorax Hymenoptera
phenetic classification Classification based on degree of overall similarity Classification
phenotype The total characteristics of an individual (its appearance) resulting from interaction between its genotype and its environment Classification
pleural membrane Membrane of the lateral pleurites General
pleural suture A suture on a thoracic pleuron extending from base of wing to base of coxa General
pleuron Lateral area of a thoracic segment General
plumose Feathery Antennal forms
post-vertical bristles In Diptera, in the middle of the upper part of the occiput Diptera
posterior Hinder, or hindmost; opposed to anterior General
precedence The order of seniority of available names or nomenclatural acts determined by application of the Principle of Priority Classification
prepectus Chitinized sclerite separating the pronotum from the tegulae Hymenoptera
pretarsus The terminal limb segment; in insects, comprising usually a pair of lateral claws and reduced median parts (arolium) General
primaries The anterior or forewings Wing
principle of binomial nomenclature The principle that the scientific name of a species, and not of a taxon at any other rank, is a combination of two names (a binomen) Classification
principle of homonymy The principle that the name of each taxon must be unique Classification
principle of priority The principle that the valid name of a taxon is the oldest available name applied to it Classification
principle of typification The principle that each nominal taxon in the family group, genus group, or species group has, actually or potentially, a name bearing type fixed to provide the objective standard of reference by which the application of the name is determined Classification
pronotum The dorsal section of prothorax; 1st segment of thorax Thorax
propodeum That part of thorax just above insertion of abdomen, really the first abdominal segment Hymenoptera
propodium Posterior portion of thorax, actually the 1st abdominal segment united with thorax Hymenoptera
prothorax First or anterior thoracic segment Thorax
proximal That part of an appendage nearest the body General
ptilinal Refers to ptilinum, a bladderlike structure that everts from top of head during emergence of adult flies Diptera
radius vein Third of the longitudinal veins caudad of subcosta, starting from base, no more than 5 branches Wing
red label Color of specimen label assigned to holotype Classification
redescription A more or less complete statement of the observed characters of a taxon, without any special emphasis on those which distinguish it from other closely related taxa, including new or altered information to that usually given in the description Classification
reticulate Like a network, sculptured General
revision The presentation of new material or new interpretations integrated with previous knowledge through summary and reevaluation for a particular taxon Classification
s.l., s. lat., sens. lat., sensu lato In a broad sense Latin Abbreviations
s.s., s. str., sens. str., sensu stricto In the strict sense Latin Abbreviations
scape Basal segment of antenna Antenna
scientific name Formal nomenclatural designation of a taxon Classification
scopa A thick brush of hairs;covering the posterior tibia of pollen-gathering forms Hymenoptera
scrobe Groove on the side of the mandibles Coleoptera
scrobe Groove at the side of the rostrum (Rhyncophora) to receive the scape of antennae Coleoptera
scrobe Groove formed for the reception or concealment of an appendage General
scrobe Circular impression upon the frons in which the scapes revolve Hymenoptera
scrobe Pit in which the antennae are set Orthoptera
scutellum A triangular plate on back between bases of wings Coleoptera, Hemiptera, Homoptera
serrate Sawlike, segments in distal half triangular in shape Antennal forms
setaceous Bristlelike, segments becoming more slender distally Antennal forms
setaceous Bristlelike (see also antennae) General
sp. nov., sp. n., species nova New species Latin Abbreviations
sp., species, Species, singular Latin Abbreviations
species group The taxonomic categories species and subspecies Classification
spiracle External opening of the breathing system, usually round or oval in shape General
spp., species Plural of species Latin Abbreviations
spurious False or incomplete Diptera
spurious vein Certain folds or thickenings in the wing surface which resemble a vein so nearly as to be readily mistaken for a vein Diptera
squama A small scale above the halteres Diptera

status novus, stat.nov. New status, representing a change in status Latin Abbreviations
sterna Plural of sternum General
sternal Referring to sternum or ventral body regions General
stigma A dense, often discolored portion of the costal margin of a wing, usually at the end of the radius Wing
stylate Last segment bearing an elongate terminal fingerlike process Antennal forms
stylus Short, slender, fingerlike process Thysanura
sub. gen. Subgenus Latin Abbreviations
subcosta vein Generally unbranched, longitudinal vein extending parallel to the costa, reaching the outer margin before the costa Wing
subsp. Subspecies Latin Abbreviations
subspecific name The 3rd (third) name in a trinomen Classification
supr. cit., supra citato Cited above Latin Abbreviations
synonym Each of 2 or more different names applied to a single taxon Classification
synonymy The relationships between different names applied to the same taxon. A chronological list of taxonomic names which have been applied to a single taxon, including authors and dates. When this includes full bibliographic references for the name = Full Bibliographic Synonymy Classification
syntype Each specimen of a type series from which neither a holotype nor a lectotype has been designated. The syntypes collectively constitute the name-bearing type Classification
systematics Studies of the kinds and diversity of organisms and of any and all the relationships among them i.e.The science of the diveristy of organisms Classification
tarsal formula Number of segments in pro-,meso-, and metatarsi (expressed as 5-5-5) Coleoptera
tarsomere Tarsal segment General
tarsus Distal or apical portion of leg, bearing claws (1-5 segments) Leg
tautonymy One and the same name applied both to a genus-group name and to an included species-group name e.g. Bison bison Classification
taxonomy Studies of the relationships of taxa, including positional changes which do not involve changes in the names of taxa Classification
tegmen Thickened or leathery front wing (plural = tegmina) Orthoptera
tegula Small scalelike structure overlapping base of front wing Hymenoptera
tegulae Small, more or less cup-like scales at the base of primaries in many insects, specifically Hymenoptera Hymenoptera
tenaculum Minute structure on ventral side of 3rd abdominal segment that serves as a clasp for furcula Collembola
tergum Plate on dorsal surface of abdomen General
thorax Second of 3 body regions, bearing legs and wings General
tibia 4th segment of leg, between femur and tarsus Leg
topotype A specimen collected at the type locality, not necessarily part of the type series and not regulated by the Code Classification
trachea Tubular breathing system of insects, marked externally by a circular opening or spiracle General
trinomen The combination of a generic name, a specific name, and a subspecific name, that together constitute a scientific name subspecies Classification
trochanter 2nd segment of leg, between coxa and femur Leg
tympanum Vibrating membrane; auditory membrane or eardrum Orthoptera, Diptera, Coleoptera, Mantodea
type The standard of reference for determining the precise application of a name. Each taxon has, actually or potentially, a type Classification

type genus Type of a nominal family is the nominal genus Classification
type locality The geographical location of the occurrence of the population from which the type specimen (holotype, lectotype or neotype) was taken Classification
type material A collective term for all type specimens. Zoologists should ensure that such material is transferred as quickly as possible to public institutions where their safety is guaranteed Classification
type species Type of a nominal genus is the nominal species Classification
type specimen Type of a nominal species is a specimen Classification
ventral Bottom surface of body General
vertex Top of head, anterior to occipital suture General
vibrissae Curved bristles or hairs in some Diptera, situated between the mystax and antennae Diptera
wing pads External expression of wing in immature insects, before eclosion General
yellow label Color of specimen label assigned to paratype(s) Classification
zoological nomenclature The system of scientific names for animal taxa and the provisions for the formation, treatment, and use of those names Classification