Question of the month

My, what big jaws you have!

My wife found this fluffy little animal with big jaws in the washing machine after a load of clothes. Very curious as to what it might be. Thank you.

Answer

Lacewing larva, held by one of its enormous pincer-like jaws. Photo: David Hardy.
A lacewing larva lurks beneath a hide constructed from debris. Photo: Steve Wilson.An adult lacewing (Norfolius howensis). Photo: Bruce Cowell, QM.
These lacewing larvae have just hatched from eggs laid on distinctive stalks. Photo: S. Wilson

You have found a lacewing larva. Adult lacewings are named for the complex vein structures in their wings. They are mainly nocturnal and often attracted to lights. Most have a weak, fluttering flight.

It is obvious from those large, curved jaws that your insect is a predator. Lacewing larvae are generally slow-moving ambush hunters. Lying virtually invisible, they grab small insects such as soft-bodied bugs that blunder within reach. Those fearsome-looking jaws are hollow. They are designed to puncture their prey, hold it securely and suck up the juices.

The most famous lacewing larvae are the antlions that dig conical pits in loose sand. They bury themselves at the bottom and flick sand up to knock victims such as stray ants into their waiting jaws. However, many other larvae such as the one in your washing machine, are roving predators that hide among vegetation and leaf litter.

Its fluffy, rough texture is made up of odd bits of detritus that the insect has gathered as an aid to camouflage. These have been placed over its back where they become entangled in long coiled hairs. Some species also add the desiccated remains of their victims, sucked dry of their body fluids, among their adornments.

Lacewing larvae are not alone in covering their bodies with objects for camouflage. Some assassin bugs and spiders employ the same tactic. In the marine environment, decorator crabs adorn themselves with living sponges, anemones and hydroids, and some even use hooked bristles to hold them in place, rather like the hairs of the lacewing larvae.

Self-adornment with debris for camouflage reflects some interesting evolutionary processes. The animals must first recognise the debris as something they can use for camouflage, and they require some physical modifications to ensure the material will stick.

Some of the earliest known examples of this behaviour are fossilised lacewing larvae, some more than 130 million years old, perfectly preserved in amber. Clearly, the ability to hide behind assorted bits of debris has a long and very successful history.

So watch out for that lump of fluff in the corner of your kitchen. There might just be more to it than meets the eye!

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