Explanation of Terms Used in Entomology | Page 3

stage.
Abdominal: belonging or pertaining to the abdomen.
Abdominal feet: see pro-legs.
Abdominal groove: the concave lobe of the inner margin of secondaries

enveloping the abdomen beneath, in some butterflies.
Abdominal pouch: in female Parnassiids, a sac-like ventral cavity,
formed by material secreted during copulation.
Abductor: applied to muscles that open out or extend an appendage or
draw it away from the body: see adductor.
Abductor mandibulae: the muscle that opens the mandibles.
Aberrant: unusual; out of the ordinary course.
Aberration: a form that departs in some striking way from the normal
type; either single or occurring rarely, at irregular intervals.
Abiogenesis: spontaneous generation.
Abnormal: outside the usual range or course; not normal.
Aborted: a structure developed so as to be unfit for its normal function
obsolete or atrophied.
Abraded: scraped or rubbed.
Abrupt: suddenly or without gradation.
Abscissus: cut off squarely, with a straight margin.
Absconditus: hidden, concealed; retracted into another.
Acalyptrata: those muscid flies in which alulae are absent or
rudimentary.
Acanthus: a spine, spur or prickle.
Acaudal -ate: without a tail.
Accessory: added, or in addition to.

Accessory carinae: in Orthoptera the lateral carinae of the face.
Accessory cell: a cell not commonly present in the group; in some
orders of definite location as, e.g. in Lepidoptera, usually a small cell at
the end of the subcosta, giving rise directly or indirectly to veins 7 to
10:= 1st radius 2 (Comst.); = areole.
Accessory glands: any glands opening into the ducts of the
reproductive system.
Accessory sac: a glandular structure of the female reproductive system
containing a sticky secretion.
Accessory subcostal vein: the vein given off from the subcosta and
branching toward the apex of the wing in Perlidae.
Aceous or aceus: suffix; similar to, or of the nature of.
Acephalous: without a head.
Acerata: arthropods without true antennae Arachnids and Limulus
Acetabular caps: Hemiptera; the coxal cavity.
Acetabuliform: like a shallow saucer with more or less incurved sides.
Acetabulum: the cavity into which an appendage is articulated;
specifically the coxal cavity, - q.v.; also applied to a cup-like cavity in
the sucking mouth of maggots.
Achreioptera: ordinal term proposed for the coleopterous family
Platypsyllidae.
Achromatic: free from color; tissue that does not stain readily.
Acicular: needle-shaped; with a long, slender point.
Aciculate: a surface that appears as if scratched with a needle.

Acidotheca: the pupal sheath of the ovipositor.
Acini: granulations, like those on a blackberry: the terminal secreting
tubes of glands.
Acinose -ous: a surface set with acini.
Acone: applied to compound eyes in which the individual ocelli have
no crystalline cone or lens; see eucone. {Scanner's note: this is no
longer a valid usage for the word "ocelli". Currently the term is. See
"ocellus" and "ommatidium".}
Acoustic nerve: connects the auditory pits or other organs of hearing
with special ganglia.
Acridophagus: preying and feeding on grasshoppers.
Acrostichal bristles: Diptera; two rows of bristles on the middle of the
dorsum; specifically, minute peculiar bristles on the dorso-central
region of Dolichopodidae.
Aculeata: Hymenoptera; the stingers, including bees and wasps.
Aculeate: prickly; armed with short, sharp spines; specifically, in
Hymenoptera furnished with a sting which is a modified ovipositor and
connected with a poison sac.
Aculeus -ei: a prickle; a small sharp point; specifically, an ovipositor,
especially when sting-like, as in Hymenoptera; in male Tipulidae a
slender, horny, often curved and pointed piece, projected when the
forceps is open.
Acuminate: tapering to a long point.
Acupunctate: a surface with fine punctures as if made with a needle.
Acutangulate: forming, or meeting in an acute angle.
Acute: pointed: terminating in or forming less than a right angle.

Acutilingual: with a sharp pointed tongue or mouth structure, as in
some bees.
Acutilingues: bees with a short pointed tongue: see obtusilingues.
Addorsal: close to but not quite on the middle of the dorsum.
Addorsal line: in caterpillars, is longitudinal, a little to one side of the
dorsal and between it and the subdorsal line.
Adductor: applied to muscles that draw an appendage to the body or
bring parts into apposition: see abductor.
Adductor mandibulae: the muscle that draws in or closes the mandible.
Adeloceratous: with concealed antennae: see cryptocerata.
Adephagous: belonging to the Adephaga: pentamerous, predatory,
terrestrial beetles with filiform antennae and predatory habits: see
hydradephagous.
Adherent: attached or clinging to.
Adipose: fat or fatty: see fat-body.
Adiscota: insects that develop into adults without forming imaginal
discs; see discota.
Adminicula: supports or props: the spinous processes on the abdomen
of boring and burrowing pupae.
Adnate: adjoining; adhering or growing together: closely connected.
Adpressed: laid or pressed to; contiguous.
Adsperse -us: with markings of closely crowded small spots.
Adsternal: situated next or close to the sternum.

Adult: the stage when an insect is sexually mature and ready to
reproduce normally.
Aduncate -cus, -catus: a part gradually bent through its whole extent.
Adventitious: occurring accidentally, out of