July 2018

Flying antennae

Note the very, very long antennae of the cranefly Megistocera filipes. It also has distinctive wing veins and markings.
Credit: Anne Hornstra.

I found this intriguing-looking insect in a sealed tank of tadpoles. Is it a cranefly and if so, how did it get there? Is that long extension from the head incredibly long antennae or its proboscis? I can't see whether the point of attachment is the head or mouth!


Answer

Credit: Anne Hornstra.

Yes, this striking insect is a cranefly. This particular species (Megistocera filipes) is not often seen or photographed although they are widespread in Australasia and south Asia. It would have hatched from an egg that was in the water with the tadpole eggs in your tank. Most cranefly species lay eggs in wet soil or decomposing plant matter.

The spectacularly long antennae are a feature of the males only and it’s possible that they are used to locate a female.

Credit: Peter Woodall.

Craneflies belong to the family of flies known as the Tipulidae which is made up of more than 11,000 species worldwide. The adults are short-lived and may only survive for days or a few weeks. Some don’t even feed as adults – their role is to find a mate and reproduce.

Credit: Peter Woodall.

Although those long legs and wings make craneflies look a bit like giant mosquitoes, they do not bite. The larvae are maggot-like and are either aquatic or live in boggy conditions. In large numbers they can damage the roots of plants.

*In 1935 a London plague of cranefly larvae affected the Lords Cricket Ground. Larval activity led to bald patches on the pitch as well as an influx of starlings trying to eat them. The subsequent pockmarking of the ‘hallowed Lord’s pitch’ by the hungry starlings and interference with the players concentration caused headaches for all concerned!

*Cricket Grounds: The Evolution, Maintenance and Construction of Natural Turf Cricket Tables and Outfields (1991).  By Roger D. C. Evans

Queensland Museum's Find out about... is proudly supported by the Thyne Reid Foundation and the Tim Fairfax Family Foundation.