abdomen - the posterior region of an insect's body
antennae - a pair of segmented projections from the anterior region of an insect's head; sensory function
apex (pl., apices) - any part of a structure furthest away from the body
apical - farthest from the body
basal - closest to the body
base - any part of a structure closest to the body
bifid - coming to two distinct points
bristle - a stiff, short, blunt hair
carnivore - an animal that feeds exclusively on other animals
caudal filaments - segmented projections from the posterior of an insect's abdomen; outer two are known as lateral caudal filaments and inner one is known as middle caudal filament; sensory function
compound eyes - image-forming eyes on the lateral surface of an insect's head
coxa (pl., coxae) - the first segment of an insect's leg, counting from the base out
denticles - small, tooth-like projections from the inner surface of an insect's tarsal claw
disjunct - separated
dorsal - the upper surface of an insect's body
femur - the third segment of an insect's leg, counting from the base out
forceps - clasping projections from the posterior of an adult male mayfly's abdomen; used for holding onto the female during mating
forelegs - the anterior pair of legs; projecting from an insect's prothorax
forewing pad - developing forewing located on a mature nymph's mesonotum
frontal process - an anterior projection from the anterior surface of an insect's head
geotropic - responding to gravity
gills - flattened or filamentous projections from a mayfly nymph's abdominal segments; used for respiration
head - the anterior region of an insect's body
hindlegs - the posterior pair of legs; projecting from an insect's metathorax
hingwing pad - developing hindwing located on a mature nymph's metanotum
hypopharynx - an insect's "tongue"; used for manipulating food in the mouth
imago - the second adult stage of a mayfly; has wings and is capable of reproduction
instar - any life stage between a molt; ex. nymphal instar
labium - the part which forms the "lower lip" of an insect's mouth; with palps for sensing and manipulating food into the mouth
labrum - the part which forms the "upper lip" of an insect's mouth; used to prevent food from falling out of the mouth
lamella (pl., lamellae) - each separate component of an insect's gill
lateral - the left and right sides of an insect's body
mandibles - mouthparts with a serrated edge for chewing food
maxillae - mouthparts with palps for sensing and manipulating food into the mouth
mesonotum - the dorsal surface of an insect's mesothorax
mesothorax - the middle segment of an insect's thorax
metanotum - the dorsal surface of an insect's metathorax
metathorax - the posterior segment of an insect's thorax
midlegs - the middle pair of legs; projecting from an insect's mesothorax
molt - the shedding of an insect's exoskeleton; allows for growth during the immature stages of an insect's life cycle
nymph - the immature stage of an insect; lacks functional wings and reproductive structures
obligately parthenogenic - reproduces by asexual means only
oblique - at an angle
ocelli - light-sensitive eyes on the dorsal surface of an insect's head, usually between the compound eyes
omnivore - an animal that feeds on both plant and animal material
oviducal openings - external openings to the paired oviducts of an adult female mayfly
phototactic - responding to light
posterolateral projections - posterior projections from the posterior sides of an insect's abdominal segments
pronotum - the dorsal surface of an insect's prothorax
prothorax - the anterior segment of an insect's thorax
sclerotized - thickened and hardened
spine - a thick, thorn-like projection
subimago - the first adult stage of a mayfly; has wings but is not capable of reproduction
substrate - the surface on which an insect lives
substratum (pl., substrata) - any object attached to or situated upon the bottom of a water body; ex. aquatic plants or rocks
synchronously - occurring at the same time
tarsal claw - a small projection from the apical end of the tarsus of an insect's leg
tarsus (pl., tarsi) - the fifth segment of an insect's leg, counting from the base out
thorax - the middle region of an insect's body
tibia (pl., tibiae) - the fourth segment of an insect's leg, counting from the base out
tooth - a short, pointed projection from an appendage
transverse - from side to side
trochanter - the second segment of an insect's leg, counting from the base out
tubercle - a small knob-like or rounded projection
undulations - wavy motions
ventral - the lower surface of an insect's body
villopore - a ventral patch of stiff hairs at the base of the femur of a mayfly's foreleg