The insect leg (generalized...
Transcript of The insect leg (generalized...
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The insect leg(generalized Orthoptera)
leg of Weta
3. femur
4. tibia
2. trochanter
6. pretarsus
1. coxa tendencytowardfusion
tendency towardfusion with thorax
plantulae
Significance ofmultiple tarsomeres:
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5. tarsus (with 4 tarsomeres)
male Aukland Tree Weta
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Leg modifications
Unspecialized (homonomous)
More specialized(heteronomous)
Plecoptera
Coleoptera(harlequin beetle)
Muscoid Diptera (legless)
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LOCOMOTION:I. Natatorial legs
Whirligig beetle(Coleoptera: Gyrinidae)
Water boatman(Hemiptera: Corixidae)
Backswimmer(Hemiptera: Notonectidae)
Water strider(Hemiptera: Gerridae)
pretarsustarsus
swimmingblades
tibia
femur
trochanter
coxa
(note “feathering” of tarsi, like oars)
ungues
Caeliferan Orthoptera
Ensiferan Orthoptera
LOCOMOTION:II. Saltatorial
Fleas:Siphonaptera
Hymenoptera: Encyrtidae
Hemiptera: Cicadellidae
tarsus
tibiafemur
trochantercoxa
p.t.
mesothoracicleg
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Mole cricket(Gryllotalpidae:
order Orthoptera)
Cicada nymph(Cicadidae:
Auchenorrhyncha:order Hemiptera)
Scarab beetle(Scarabaeidae:
order Coleoptera)
LOCOMOTION: III. Fossorial (showing convergence in 3 orders)
tarsus
tarsus
tarsus femur
femur
femur
coxa
coxa
coxa
trochanter
trochanter
trochanter
Mole cricket –Orthoptera:
Gryllotalpidae
Cicada nymph –Hemiptera:Cicadidae
Scarab beetle –Coleoptera:
Scarabaeidae
GRASPING: I. Raptorial(showing convergence in 2 orders)
MantisflyNeuroptera: Mantispidae
Preying mantis(Dictyoptera: Mantodea)
tarsus & pretarsus
tarsus &pretarsus Diving beetle
(Coleoptera: Dytiscidae)
tibiafemur
trochanter
coxa
“eye” spot
prothorax
(partial fusion)
spur
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More raptorial legs: Hemiptera, Orthoptera, Lepidoptera
Belostomatidae
Hemiptera:Belostomatidae
Hemiptera: Nepidae
Hemiptera:Reduviidae
Orthoptera:Tettigoniidae
Lepidoptera:Geometridae
GRASPING: II. Ectoparasites
An adult muscoid fly, ectoparasitic on bats(fam. Nycteribiidae, Muscoidea, order Diptera)
Pubic louse, ectoparasitic on humans(Anoplura, ‘Phthiraptera,’ Psocodea)
tarsus
tibia
femur
pretarsus
tibialspine
tarsal spur
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STRIDULATORY legs: Acrididae (Orthoptera)
POLLEN-CARRYING legs in the honey bee, Apis mellifera
coxa
trochanter
femurtibia
pretarsus
tarsus
rake
press
press
corbicula
combs
INNER ASPECT OUTER ASPECT
rake
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OTHER specialleg modifications
Antenna cleaner(foreleg of honey bee)
Tympanal organ(foreleg of cricket
or katydid)
Female hold-fast organs(foreleg of male ,
a diving beetle)Dytiscus
Tympanalorgans
SENSATION:
tibia
tarsus
femur
coxa
trochanter
coxa
trochanter
femur
suctiondisks
1st tarsal segment (tarsomere)
antenna cleanerspine
ANTENNA CLEANER(foreleg of honey bee)
TYMPANAL ORGAN(foreleg of cricket & katydid
HOLD-FAST ORGANS(foreleg of male Dytiscus,
a diving beetle)
SPINNERETS(foreleg of Embioptera)
tarsomerestibia
silkejectors
SEXUAL DISPLAYS
CRYPSIS, for aggression (tropical mantis: Mantodea)
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CRYPSIS, for defense (orders Phasmatodea & Lepidoptera)
Hornet clearwing moth (Paranthrene)
Leaf insectStick insect
FALSE legs (prolegs)
Lepidoptera caterpillar
Sawfly larva (Hymenoptera)
Coleoptera larvacrochets
Diptera larva
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Origin of Insect Wings: Prerequisites
• A flap of reasonable size, positioned amid-ships
• Some sort of articulation, to allow movement
• Muscles to flap it up and down and control the structure
• A pre-existing function for the structure while it is small