Shape-shifting bug

Hopper adult and nymph
Leaf-hopper (Flatidae) adult and nymph

This picture could well have appeared in my gallery of microfauna a few days ago but I thought it deserved a little more prominence.

What do we have? Two insects on a plant stem, obviously. Two completely unrelated insects, most of us would think – like a man and his dog leaning against opposite sides of a lamp-post, for instance – but we would be wrong: they are the same species. The one on the right is a juvenile – a nymph – of the larger winged insect on the left.

They are Hemiptera – ‘true bugs’. The adults are known as leaf-hoppers or plant-hoppers and these two are probably Colgar rufostigmatum or Colgaroides acuminata in the family Flatidae. The nymphs, as far as I can tell, are not known as anything at all. They are only about 5mm long without the peculiar tail of waxy filaments and are easily overlooked. The adults are more visible, at 8mm or so, but can easily be mistaken for a spine or new leaf on the stem of the plant. Like many Hemiptera, they feed exclusively on sap they suck from the plant.

Insects of many families undergo radical transformations during their life cycle, of course. The caterpillar-pupa-butterfly sequence is well known (but still amazing); cicadas spend their long childhood underground, eating roots, and dig their way out to split open and take wing; dragonflies spend their infancy as ugly aquatic predators before climbing out and emerging as adults; and so on. By comparison mammals (like us) are boring  …  just about all we do is get bigger.