Flyfishing Entomology






abdomen third (of three) major body segment of insects
aerobic living in an environment where free oxygen is used for respiration
aestivation passing hot or dry periods in a torpid state
air straps a pair of abdominal segment 8 appendages of giant waterbugs used for respiration
alate winged
algae aquatic plants having chlorophyll, and not having true roots, stems, or leaves
ametabolous without change in body form during development to adult
amorphous not having any definite form
anaerobic not requiring free oxygen for respiration
anal pertaining to the most posterior part of the body
anal vein the 6th major longitudinal vein of insect wings
anastomosed crisscross-like network of veins, usually in stigmatic area of wing
annulated having ring-like segments
antenna a variously shaped appendage of the head
anterior the forward part of the body
apex tip, end, or highest point of structure
apical at the end or tip of a structure
apolysis separation, but not casting off, of larval integument from pupal integument
apotome small plate in middle of underside of head
apterous being wingless
aquatic living in or on water
basal at the base of a structure
benthic bottom-dwelling organisms
bifid coming to two distinct points
binomial scientific name, composed of genus and species
bivoltine two generations completed in a single year
brachypterous having shortened wings
bristle a stiff, short, blunt hair
brood a clutch of individuals that hatch at the same time from eggs of one set of parents
bulla bubble node or blister usually found midway along the subcostal vein of insect wing
burrower a benthic insect that tunnels into the soft bottom substrates
campodieform grub-like (as are some caddisfly larvae)
carapace a hardened shield covering part of the body dorsally
carnivor an insect that feeds off living animal material
caudal pertaining to the anal end of the insect body
cerci slender segmented (normally paired) appendages on the 10th abdominal segment
cervical pertaining to area immediately behind head and before thorax
cervix the neck, or especially the back of the neck of insects
chitin a hard secretion of the epidermis, major component of arthropod cuticle
chloride cells whose function is uptake of ions from the water
collar rounded or flattened anterior margin of prothorax
clasper paired, jointed structure of male adult mayfly used to clasp female abdomen during mating
clavopruina white frosted valley on forewing of adult waterboatmen
climber a benthic insect that commonly resides on aquatic plant stems, etc.
clinger a benthic insect that clings steadfastly to substrates
coleopteroid beetle-like in form, referring to structure of forewings
costa the 1st longitudinal wing vein; the thickened front margin of the wing
coxa the basal, or first, segment of the leg
CPOM coarse particulate organic matter (organic particles > 1 mm.)
crochets curved hooks, spines or spinules on prolegs
cross-veins transverse wing veins that link the longitudinal veins
cubitus the 5th longitudinal vein of insect wings
culm the stem of grasses or sedges
cutaneous term for respiration where insects obtain oxygen directly through body wall
cuticle the external skeletal structure composed of chitin and protein
denticles tooth-like projections
detritivore an eater of organic detritus of plant or animal origin
detritus dead and decomposing plant or animal material
diapause resting stage with reduced metabolic activity
diatom a unicellular form of algae
diel pertaining to a 24-hour period or a regular occurrence in every 24-hour period
dimorphic male and female differ considerably
disjunct separated
distal at or toward the end of a structure
diurnal active during daylight hours
dorsal pertaining to the top or upper surface
ecdysis the casting off of the larval integument
eclosion the process of hatching from the egg
ecology pertaining to the relationships of organisms and their environment
ecosystem all of the component organisms of a community and their environment
elytra the front chitinous wings of beetles which cover and protect the hind wings
emergence transformation to the adult stage
entomology the study of insects
epiproct a dorsal relic of abdominal segment 11
eruciform caterpillar-like (as are some caddisfly larvae)
eutrophic an aquatic environment rich in nutrients and biological productivity
exoskeleton the external body wall of arthropods
exuvia a cast skin or nymphal shuck
eyespot a single eye or eyelike structure found on the head
facet lens-like divisions of compound eyes
femur the third (often stoutest) segment of an insect leg, following the coxa and trochanter
fibrils threadlike gill filaments of some mayfly nymphs
file a toothed or ridged structure used in sound production by contact with a scraper
flagellum the third part of an antenna, distal to the scape and pedicel
forceps clasping projections from the posterior of an adult male mayfly's abdomen
fossorial adapted for burrowing or digging, as in fore tibia of burrowing mayfly
FPOM fine particulate organic matter (organic particles > 5 um. & < 1 mm.)
frenulum spines or bristles on costa of hind wing that lock with forewing retinaculum in flight
ganglia collection of nerve cells acting as center of nervous influence
generation the complete life cycle of an insect
genitalia external sexual organs or structures
geotropic responding to gravity
gills respiratory appendages of nymphs
gravid having fertilized eggs
halteres the modified hind wings of Diptera, acting as a balancers
head the most anterior region of an insect's body
hemelytron the partially thickened forewing of waterbugs
hemimetabolous undergoes incomplete metamorphosis (no pupal stage)
hemolymph the internal body fluids of arthropods
herbivore a plant feeder, specifically of living plant tissue
hindlegs the pair of legs projecting from an insect's metathorax
holometabolus undergoes complete metamorphosis (including pupal stage)
hyaline glassy, transparent, usually in reference to wings of spinner
hypopharynx an insect's "tongue" used for manipulating food in the mouth
imagio the adult stage of an insect
incubation period during egg stage necessary for development and subsequent eclosion
instar insect between two molting events
integument the outer covering of the living tissues of an insect, epidermis plus cuticle
intercalary in mayfly, short veins not connected to main longitudinal veins
intermittent description of streams with water flow only part of the year
interstitial located in small or narrow space (crevice) between objects
labium the lower lip of an insect
labrum the upper lip of an insect
lacinia apex of the maxilla
lamella a leaflike gill located at the end of the abdomen of damselfly nymphs
lanceolate lance-like, as in gills of some mayfly nymphs
larva first major mobile life stage or form of insects
lateral at or toward the sides
lentic aquatic environments with nonflowing water
ligula tongue or strap-like central appendage of the labium
limnetic open-water zone of lakes beyond zone of emergent vegetation
littoral near-shore zone of ponds and lakes
lotic aquatic environments with flowing water
macropterous having long wings
macrovore an insect whose food items are generally larger than 10 cubic microns
maggot a legless larval insect, usually with a reduced head, frequently a fly.
mandibles the first pair of jaws in insects
maxilla second pair of jaws of mandiblulate insects
media the 4th major longitudinal vein of insect wings
medial at or toward the midline of the body
merovoltine one generation completed in (three or more) years
mesonotum top or dorsal area of mesothorax
mesosternum bottom area of mesothorax from which middle pair of legs are attached
mesothorax the second (middle) thoracic segment
metamorphosis series of changes an insect passes through during development from egg to adult
metanotum top or dorsal area of metathorax
metapleuron in mayfly, side area of metathorax, from which base of hind wings are attached
metathorax the third thoracic segment
microboita microscopic organisms
microvore an insect whose food item are generally less than 10 cubic microns
midge a generic term used to describe any minute insect
midlegs the pair of legs projecting from an insect's mesothorax
miner an insect that feeds on leaf tissue by tunneling within the leaf itself
molting the formation of a new cuticle followed by ecdysis
morphology the study of the structure and form of organisms
mutic without spines
naiad larval stage of insects with incomplete metamorphosis
natant floating, the emergent nymphal stage
natorial fitted for swimming, generally applies to swimming legs in aquatic bugs
notum dorsal surface of a body segment
nymph larval stage of an insect which undergoes incomplete metamorphosis
ocelli simple eyes consisting of a single beadlike lens
oligotrophic an aquatic environment having a low level of nutrients and biological productivity
omnivore an animal that eats both living plant and living animal matter
operculate having a flap-like gill covering succeeding gills as in some mayfly nymphs
organism any living individual plant or animal
ova eggs of female adult
oviposition the act of laying eggs
ovipositor specialized structure of female adults of certain insects used to lay or deposit eggs
ovoviviparity eggs remain in female until the hatch or are about to hatch
pala hair fringed tarsus of adult waterbug
palp a segmented finger-like appendage attached to the maxilla or labium
papilla a thin walled structure of certain insects and used for ion uptake
paraproct ventral relics of abdominal segment XI
parthenogenic refers to reproduction without mating or egg fertilization
pectinations toothed, comblike spines in tarsal claw
pedicel the second antennal segment
palagic living in open oceans or seas
penes paired structures of male for transfer of sperm to female eggs
periphyton a complex matrix of algae and heterotrophic microbes attached to submerged objects
petiole the stalk by which a leaf is attached to the stem
pharate the newly formed adult that still resides within the pupal skin
pheromone insect-produced chemical signaling its presence to other members of same species
phoretic use of one organism by another as a means of transportation
phototactic responding to light
plankton organisms that live suspended in water and have little or no power of locomotion
plastron a thin film of air held by many tiny unwettable hairs
plueon the lateral region of any segment of the insect body
polypod a type of larva with jointed legs on the thorax and prolegs on the abdomen
polyvoltine more than one generation completed per year
posterior the hind part of the body
posterolateral referring to the back and sides
prey an animal attacked and eaten by a predator
proboscis elongate mouthparts
profundal pertaining to the deep-water zone of lakes below the depth of light penetration
proleg a fleshy, unsegmented, leglike structure of a larva
pronotum dorsal area of prothorax
propleuron side area of prothorax
prosternum bottom surface of prothorax, from which forelegs are attached
prothorax the first thoracic segment
proximal the part of an appendage closer to or at the body (opposite to distal)
pupa the life stage that immediately precedes adult in an insect with complete metamorphosis
puparium the thickened and hardened larval skin in which the pupa is formed
pupation the act of becoming a pupa
quadrate more-or-less square-shaped
radius the 3rd major longitudinal vein of insect wings
raptorial adapted for seizing prey
rheophilic found in flowing waters, usually with strong currents
riparian typically occurring or growing along the banks or rivers or streams
saltatorial adapted for jumping or springing
saprophagous an eater of decaying organisms
scale a flat unicellular outgrowth of the body wall
scape the first segment of the antenna
scavenger a feeder on dead animals
sclerite a plate on the body wall surrounded by membrane or sutures
sclerotized definite hardened areas of the insect exoskeleton
scraper the ridged surface drawn over a file to produce stridulatory sounds
screen basic device for sampling aquatic insect life in a stream
scutellum in beetle adults, a small dorsal, triangular area found medially at the base of the elytra
scutellum in caddisfly adults, a large dorsal area on the mesothorax behind the pronotum
scutum the medial, posterior, and dorsal area of the mesothorax of caddisfly adults
sector a major wing-vein branch and all of its subdivisions.
semi-aquatic living in saturated soils, but not immersed in free water
semivoltine one generation completed in two years
sessile attached and incapable of actively moving from place to place
seston all of the suspended solid matter in a column of water
setae sclerotized hair-like projections
shuck the empty exoskeleton left behind after molting occurs
silt substrate material composed of very small particles
sinuate bending or curving as opposed to straight
species a group of alike individuals that can interbreed producing fertile offspring
spine a multicellular unjointed cutecular extension, often thorn-like 
spiracle external opening of the tracheal system along the body wall
sprawler a benthic insect that crawls about on substrates
stadium the time interval between two larval instars
stemmata the simple lateral eyes of insect larvae with complete metamorphosis
sterna the ventral or bottom surface of body segments
sternite the ventral plate of an abdominal segment
stridulation the production of sound by rubbing two rough or ribbed surfaces together
strigil sound producing file on the abdomen on adult waterbug
subcosta the 2nd major longitudinal vein of insect wings
subimagio a fully winged stage that precedes the adult in mayflies
substrate the bed or bottom of an aquatic environment
suture a line or slight furrow in the body wall
suture an external groove that may show the fusion of two plates
swarm an aggregation of insects, often for the purpose of mating
symbiotic living in close association or contact with another species
synonym one of two or more names that apply to the same species
systematics the science of biological classification
tagma segments that become fused to form a distinct region
tarsus third major leg segment, distal to the tibia
taxon a named group of organisms (species, genus, family, etc.)
taxonomy the theory and practice of naming and classifying organisms
tegmina thick, leathery hardened fore wings
teneral the adult insect shortly after emergence, before hardening and full coloration
terga the dorsal or upper portion of body segments
tergite upper or dorsal surface of an individual abdominal segment
tergum the dorsal or upper portion of any body segment
terminal pertaining to the posterior end of the body or distal end of a structure
terrestrial living on land or in the air, as opposed to aquatic
thorax second (of three) major body segments
tibia the fourth major leg segment distal to the femur
tolerance the degree to which an organism is able to endure certain environmental factors
trachea an internal elastic air tube used for transporting oxygen
transverse at right angles to the longitudinal axis
trivoltine three generations completed in a single year
trochanter the segment of the insect leg between the coxa and femur
trochantin a separate small platelike appendage in caddisfly larvae
trophic the relative position in the food web in terms of securing nutrients
truncate squared off or blunt at end
tubercle a rounded eminence or nodule
turbinate in adult mayfly eyes; faceted part on a stalk-like platform
tusks paired horn-like prominence extending from head of burrowing mayfly
univoltine only one generation completed in a single year
urogomphus process on terminal abdominal segment of certain insect larvae
veinlet short vein in wing that leads from a major longitudinal vein to the wing margin
venation structural network of veins in wing
ventral pertaining to the bottom or underside
vernal temporary or existing only part of the year
vestigal an appendage surviving in a dwarfed or degenerate form
villopore a ventral patch of stiff hairs at the base of the femur of a mayfly's foreleg
voltinism pertaining to the number of generations per year (or years)
xylophagous wood eating
zygote a fertilized egg

Created: 08/04/2004   Last modified: 03/17/2008    www.FlyfishingEntomology.com