25 Hexapoda and Myriapoda Flashcards
mandibles
mouthparts
mandibles derived from the
coxa
seta
fine cuticular hairs
seta functions
can be sensory
assist in locomotion
protective covering
camouflage
create patterns
entomology
study of insects
Insecta
class of hexapod
Collembola
Class of hexapods
springtails
Entognatha
may not be a
monophyletic group
hexapods share these features
Resp tagma
Mandibles
Limbs antennae
-1 pair of antennae
-single-articled mandibles
-tracheae and spiracles
uniramous limbs
3 tagmata: head, thorax, abdomen
Entognatha mandibles enclosed by
cheeks
entognathous
internal mandibles Entognatha
articulate with head with single condyle
Collembola species appendage
furcula
furcula function
used for
jumping
water anwater and ion regulation Collembola
collophore(ventral tube)
Collembola eyes
ocelli
why are protura unique among hexapoda
completely lacking antennae
Collembola Protura and Diplura ijn group called
Entognatha
Insecta eyes
-compound eyes
-often also have ocelli
in insects, mandibles are
ectognathous
ectognathous
mandibles are not
enclosed in cheeks
Archaeognatha
bristletails
part of insecta
bristletails mandibles
only one condyle on mandible joint
excluding bristletails, insects have mandibles with
dicondylic mandibular joint
2 condyle
Archaeognatha appendages
ventral jointed appendages on their abdomens
what did Archaeognatha and Thysanura evolve prior to
evolved prior to the evolution of wings
apterygote (no wings)
most insects have how many wings
2 pairs of wings
what are insect wings a synapomorphy of
clade Pterygota
what have some insects lots
secondarily lost wings
what is the ancestral form of wing bases
what is this caled
relatively fixed wing bases
palaeopterous condition
Neoptera
pterygote insects w more flexible wing bases
ancestral state isntead of flexible wing base
-both pairs of wings membranous
-some rigid forewings
-reduction in size of one pair
different flight muscles attachment
direct - attached to the wing
indirect - act on the thorax
cool thing bout dragonflies
both types of flight muscles attachment
dragonflies wings how do they work
dorsoventral thoracic muscles contract = pull down the notum –> clicks’ the wing base, raising the wing
the downstroke: contractions of muscles directly attached to the wing
true flies flight muscles and how do they work
indirect
dorsoventral muscles contract, and pull down the notum: upstroke
dorsal longitudinal muscles contract to ‘pop up’ notum: downstroke
hexapods sexes
separate
how do collembolans and apterygote transfer sperm
indirectly, use spermatophore
spermatophore
encapsulated package of
sperm) placed on a substrate
pterygote transfer sperm
copulate
fertilization pterygote
internal fertilization
some hexapods are
haplodiploid
haplodiploid
fertilized eggs become diploid females, unfertilized eggs become haploid males
what do Hymenoptera do
control sex ratios
Hymenoptera
bees, ants, and wasps
what do females of haplodiploid species do
control the sex of each offspring
hexapods cleavage
intralecithal with no evidence
of spiral or radial patterns
hexapods development
epimorphic
epimorphic
all body segments are present at
hatching
Hexapod life cycle variations
ametaboly
hemimetaboly
holometaboly
ametaboly
juveniles look
exactly like small adults except that
they have no genitalia
- incomplete
what groups show ametaboly
entognathous hexapods
and apterygote insects
hemimetaboly
wings develop slowly over several
moults (as wing pads)
juvenile in hemimetaboly called
nymph rather than
a larva
holometaboly
wings develop all at once
-juvenile looks different than adult
stage where wings develop all at once in holometaboly
pupa
juvenile holometaboly
larva
holometaboly is a synapomorphy of the
clade
Holometabola
Hexapod diets
predators, microbivores,
herbivores, detritivores, parasites, parasitoids
parasitoid
host is killed
parasite
doesn’t have to kill the host in order to
complete life cycle
drugs from plants
insecticidal chemicals like nicotine, caffeine used to kill oinsects
Myriapoda
many more than 3 pairs of legs
Myriapoda tagmata
head, trunk
head Myriapoda
ocelli, mandibles, 1 pr antennae
trunk Myriapoda
many uniramous legs
gas exchange system Myriapoda
spiracular/tracheal system
habitat Myriapoda
terrestrial
-oldest fossils of terrestrial animals
Diplopoda-
millipedes
pt of myriapoda
Diplopoda diet
detritivorous or herbivorous
Diplopoda legs
two pairs of legs and two stigmata per ‘segment’
result of fusing of adjacent pairs of
segments
diplosegments
what class has most legs of any arthropod
Diplopoda
main defense diplobod
thick exoskeleton that is often
calcified
glandular secretions
Chilopoda
centipedes
pt of myraopda
Chilopoda characteristics
poison claws
aggressive predators
1 pair of legs per segment
house centipede eyes
compound eyes
Myriapoda sexes
separate sexes
sperm transfer centipedes
-indirect with male placing spermatophore and female picking it up
sperm transfer millipedes
male passes the
spermatophore directly to the female
fertilization Myriapoda
internal
development Myriapoda
similar to that of
hexapods
direct
some spp epimorphic (hatch w all segments) and some anamorphic (moult to add)
cleavage Myriapoda
is intralecithal
what do female centipedes do with eggs and hatchlings
guard
