1) Long evolutionary history (540+ My) 2) broad size range/habitat utilization 3) metameric body plan/rigid exoskeleton 4) co-evolution with plants 5) evolution of flight Insect Diversity 29 orders total - 4 wingless (apterygotes) - examples: bristletails, springtails - 16 hemimetabolous winged (exopterygotes) (incomplete metamorphosis) examples: mayflies, dragonflies, grasshoppers, stick insects, earwigs, roaches, termites, true bugs - 9 holometabolous winged (endopterygotes) (complete metamorphosis) examples: lacewings, fleas, beetles, flies, butterflies and moths, caddis flies, ants bees and wasps Most insect species are holometabolous Could have something to do with mixed life cycle: offspring are ecologically different from adults Most insect biomass is from ants and termites: Each represents about 10% of all animal biomass Insect Anatomy (Head - Thorax - Abdomen) Head - bears eyes (usually compound), antennae, mouthparts Mouthparts - chewing (grasshoppers), sucking with stylet (bugs & aphids), sucking with coiled tongue (butterflies), etc. Antennae - used to detect odors or as tactile organs Thorax - 3 segments, with 3 prs. legs, winged insects normally have 2 pairs of wings Legs - 6 legs (Hexapoda) Each thoracic segment supports 1 pr. Legs are segmented Last segment often bears small claw Some have legs specialized for jumping Wings - probably arose once in common ancestor Most insects have two pairs Flies have 1 pr. (front pr. modified as halteres) Most membranous - some leathery or hard Sometimes wings bear hairs or scales Direct vs. indirect flight muscles (see Fig.
(Insect Diversity 29 orders total - 4 wingless; apterygotes; ) (Wings; probably arose; T:once in common ancestor) Context(Wings probably arose,List([1356, 1378))):(Some; have; legs specialized for jumping) Context(Some have Wings probably arose,List([1317, 1378))):(legs; specialized; for jumping) (Each; represents; about 10% of) Context(Each represents,List([793, 808))):(Most insect biomass; is; from ants and termites) Context(Most insect biomass is Each represents,List([746, 808))):(something to do with mixed life cycle; are; ecologically different from adults) Context(something to do with mixed life cycle are Most insect biomass is Each represents,List([658, 808))):(Most insect species; are; holometabolous) (wings; bear; hairs or scales Direct vs. indirect flight muscles; T:Sometimes) (caddis; flies; ) (Each thoracic segment; supports; 1 pr) (all animal biomass Insect Anatomy (Head - Thorax - Abdomen) Head - bears eyes (usually compound), antennae; mouthparts; ) (Most insects have two pairs Flies have 1 pr. (front pr; modified; as halteres)
Wings probably arose,List([1356, 1378)) Some have Wings probably arose,List([1317, 1378)) Each represents,List([793, 808)) Most insect biomass is Each represents,List([746, 808)) something to do with mixed life cycle are Most insect biomass is Each represents,List([658, 808))
Insect Diversity 29 orders total - 4 wingless Wings Some legs Each Most insect biomass something to do with mixed life cycle Most insect species wings caddis Each thoracic segment all animal biomass Insect Anatomy (Head - Thorax - Abdomen) Head - bears eyes (usually compound), antennae Most insects have two pairs Flies have 1 pr. (front pr
apterygotes probably arose have specialized represents is are are bear flies supports mouthparts modified
T:once in common ancestor
legs specialized for jumping
for jumping
about 10% of
from ants and termites
ecologically different from adults
holometabolous
hairs or scales Direct vs. indirect flight muscles T:Sometimes
1 pr
as halteres