Insect Anatomy part 2 Flashcards
what is the thorax
the second segement of three which makes up the tagmata of an insect and is usually divided up into three segments which have appendages
what are the three sections that the thorax or mesosoma is divided into
1) prothorax = pair of legs
2)mesothorax= pair of legs and wings
3) metathorax = pair of legs and wings
what are insect sclerites
a series of integumental plates connected by tough, elastic membrane= these plates have names
1) top dorsal = Nota
2) Bottom plates = sterna
3) side plates = pleura
what are the different segments of insect sclerites
Nota = upper, concave plates
pleura = lateral, convex plates
sterna = ventral sclerites
outline legs in insects
six jointed appendages with a multitude of functions
outline insect leg structure
- 3 pairs of walking legs= one pair per thoratic segment
- typically six-segmented
outline the different leg segemnts which make up leg structure
1) coxa
2) trochanter = two segment trochanter (only one muscled) occurs in Odonata and some hymenoptera
3) femur
4) tibia
5) tarsus = subdivided and typically a two clawed prtarsus
6)pretarsus
outline the coxa
- most basal aspect of the insec leg
- articulates with sternites
- joint between coxa and body wall may be monocondylic, dicondyic or more complicated
- may articulate with any of of the several small sclerites, pleura and or the sternum
outline the trochanter segement of the leg
- usually small
- a joint between coxa and femur
- joint between coxa and trochanter is always a dicondylic joint
- motion restricted to a forward and backward direction (vertical plane)
- appearance of two trochanters in odonata
outline the femur part of the leg
- usually long and stouter than other segments
- contains main muscles used in running, jumping and digging
- joint between trochanter and femur is usually fairly firmly attached or with only small amount of movement
outline the tibia part of the leg
- usually long and offers extra flexibility
- may carry spurs for defence
- joint between femur and tibiai is dicondylic
- head often bent so shank can flex against femur
outline the tarsus segement of the leg
- foot or contact surface of leg
- most insects it is subdivided from 2-5 tarsomeres
- tarsomeres = not true segments as lack individual musculature
- basal segment (basitarsus) has monocondylic articulation with tibia
- rest of joints lack true articulatory structures= freely moveable in membraneous joints
outline the pretarsus segment of the leg
- generally consists of a median lobe (arolium) and a pair or tarsal claws (ungues)
- diptera usually have no arolium but have membranous pulvilli , ungues and a middle empodium
what is a ariolium
found on the pretarsus section of the leg
median lobe may be membranous or partly sclerotised
= acts using suction from large numbers of minute tubular hairs enabling insects to hold onto smooth substrates
= none in diptera exepct in crane flies
what is an ungues
found on the pretarsus part of the leg and is used to assit the insect in holding substrate or prey