Hexapoda: the Megadiverse Orders

Question 1

Lepidoptera

Answer 1

Butterflies & Moths

Question 2

Why did all 4 groups of Lepidoptera massively diversify around 150-100 MYA ?

Answer 2

Radiation of Lepidoptera tracks diversification of Angiosperms (flowering plants)
Also true for flower-visiting Hymenoptera (bees) & Diptera (e.g. hoverflies), and the phytophagous (plant-eating) Coleoptera

Question 3

Why did the diversification of Angiosperms lead to super-radiation of insects?

Answer 3

Angiosperms tend to be more palatable (especially in terms of physical protection) than earlier plants (cycads, tree ferns, conifers etc)
Insects evolved to eat soft plants; angiosperms invested in chemical defences, leading to coevolution in chemical arms races
Evolution of flowers led to coevolution and radiation in pollinators

Question 4

Features of Adult Lepidoptera

Answer 4

Two pairs of wings covered in scales (Lepidoptera = ‘Scale wing’)
Mouthparts in form of coiled proboscis, which can be extended when feeding - usually on nectar

Question 5

Did bats drive evolution of anti-bat defences in moths?

Answer 5

Evasive flight action in response to hearing calls
Advertising their toxicity – Acoustic Aposematism
Sonar “Jamming”
Acoustic Deflection

Question 6

Lepidoptera patterns and colouring why?

Answer 6

Camouflage
Predator Deterrence
Aposematism (Warning Colouration)
Müllerian Mimicry Rings
Batesian Mimicry
Migration

Question 7

Order Lepidoptera

Answer 7

Herbivorous specialists
Wings covered by pigmented scales.
Mouthparts are modified into coiled proboscis
Holometabolous
Aposematism & mimicry common

Question 8

Angiosperms

Answer 8

A plant of a large group that comprises those that have flowers and produce seeds enclosed within a carpel