ch 21: hexapoda Flashcards
hexapods live in freshwater and terrestrial environments but do hexapods live in salt w?
no
3 tagmata
- head
- thorax
- abdomen
appendages (3)
- 3 pairs of legs
- 1 pair of antennae
- most groups have wings (4)
life history (2)
- sperm transferred via copulation
- F deposits eggs via ovipositor
hexapod digestion (2)
- thru gut w/ specialization
- internal teeth for grinding
hexapod excretory syst incl
malphigian tubules
circ (2)
- open
- heart pumps hemolymph
nervous system
brain w/ nerve cords and ganglia
what are the mouthparts derived from
3 ancestral segments that fused to form the head
mandibulate mouthparts
- for grabbing and chewing
- may be modified for fighting or grasping mates
haustellate mouthparts
for sucking
4 types of haustellate mouthparts
- stylets
- siphons/proboscis
- sponges
- chewing-lapping
stylets
modified for piercing and sucking
siphoning mouthparts/proboscis
sucking only
sponging mouthparts
draw in food w/ adhesion/cohesion
chewing-lapping mouthparts
well-developed mandibles, but maxillae and labium elongated and can form tube for sucking liq (bees)
are wings appendages?
no
what are wings
extensions of the exoskeleton
wing vein funct (3)
- carry hemolymph
- contain trachea
- useful for taxonomy and phylogeny
what are veins/trachea in the wings used for
unfurling when formed
2 theories for wing formation
- wings began as tracheal gills
- wings began as paranotal lobes, or extensions of the exoskeleton/shoulder flaps
how are wings moved?
by changing the shape of the thorax to drive wings up and down
primitive wings
- 2 pairs of many-veined wings that cannot be folded up
- opposing beats
4 things that show the trend towards action of wings as a single unit
- dec size of hind wing
- hind wings lost
- forewings not used in flight
- hind and forewings hooked together
what is weird about Aphids, life history wise?
birth live young
ametabolous development (2)
- juveniles resemble adults but lack repro structures
- in primitive wingless taxa
hemimetabolous development (2)
- juveniles/nymphs resemble adults but lack repro structures and wings
- eg. grasshoppers, true bugs, etc
holometabolous development (2)
- 4 life stages (eggs, larva, pupa, adult)
- mosquitoes, lepidopterans, etc
advantage to holometabolous development (2)
- occupy diff niches
- task allocation
disadv of holometabolous development
metamorphosis requires lots of genes, and leaves pupa stage completely helpless
diapause
seasonal delay in development
the purpose of diapause
avoiding unfavourable conditions
5 causes of diapause
- changes in gay length/temp
- dessication
- lack of food
- crowding
- host diapause
adv of diapause (2)
- avoid unfavourable conditions
- allow synchronous emergence
adv of syncronous emergence (2)
- repro
- saturating local predators
order odanata (2)
dragonflies and damselflies
odanata predation adaptations
- compound eyes
- excellent fliers
weird thing about odanata “larvae”
may take several yrs to mature
why do odanata have long mating rituals
to ensure spermatophore doesn’t get replaced
order orthoptera (3)
- katydids
- grasshoppers
- crickets
orthopteran characteristics (3)
- forewings thickened and darkened
- hemimetabolous development
- herbivores
order hemiptera
the true bugs
hemiptera characteristics (2)
- stylet mouthparts tucked underneath
- hemimetabolous
10 egs of true bugs
- bed bugs
- water striders
- giant w bugs
- cicadia
- predatory stink bug
- backswimmer
- water boatman
- ant mimic
- aphids
- spittle bugs
aphids life history (2)
- parthenogenic in summer
- winged adult m/f elsetime
order diptera
flies
4 characteristics of diptera
- holomet
- large compound eyes
- sponging mouthparts
- one pair of wings, one pair of halteres
order coleoptera
beetles
which order of insects are the most successful
coleoptera
eltyra
sclerotized forewings
2 characteristics of coleoptera
- mandibulate mouthparts
- eltyra
order lepidoptera
moths and butterflies
lepidoptera characteristics (3)
- 2 pairs of large wings
- covered in scales
- agri crop prets
adult lepi mouthparts
proboscis (sucking)
lepi appendages (2)
- 3 pairs of thoracic legs
- up to 5 pairs of abdominal prolegs
order hymenoptera (3)
- ants
- bees
- wasps
hymenoptera characteristics (2)
- 2 pairs of wings
- constriction btwn thorax and abdomen