27 May 2018 | Posted in Charlotte Owen
© Alan Price

By Charlotte Owen

WildCall Officer

May is the month of the cockchafer, a big, bumbling beetle that may look and sound a bit scary but this gentle giant is just looking for love. Its curious common name is thought to derive from “cock” meaning familiar, as in ‘cock sparrow’, and a “chafer” is a gnawing beetle in the same family as the infamous Egyptian scarab. It’s also known as the May bug, since most of them will emerge this month, but this is just one of an impressively long list of imaginative local nicknames that includes spang beetle, billy witch, dumbledarey, mitchamador and bummler.

The adults that are appearing now have spent at least three years underground as creamy-white grubs, munching on the roots of grasses and cereals.Before agricultural intensification, these larvae were serious pests and in 1320, the people of Avignon took the cockchafer to court, ordering it to leave town and relocate to a designated area. Of course, not a single cockchafer complied and thousands were rounded up and killed. Today, they exist in much lower numbers and their main predators are crows and other corvids, which love to snack on a fat and juicy cockchafer grub or ‘rookworm.’ It takes three to five years for the slow-growing grubs to reach their maximum size of around 4 cm. They will then undergo a final moult and pupate in early autumn, emerging as an adult beetle six weeks later.The freshly-emerged adults stay underground until spring, when they finally work their way to the surface and take flight.

Cockchafers are powerful but ponderous fliers. Used to a life in the dark, they fly at night and are attracted to light, frequently crashing into lit windows or careering into our homes. They only live for six to eight weeks and their sole, and sometimes frantic, mission is to reproduce. Their impressive, feathery antennae are used to pick up and track down the chemical signals released by potential mates and you can tell the sexes apart by counting the “leaves” - males have seven on their antennae, whereas females have only six. After mating, each female will lay up to 80 eggs, burying them deep in the soil before bumbling off into the night.


  • Laurence Harley:

    03 Sep 2019 16:08:00

    Extremely interesting and informative. Just about all anyone needs to know. Thank you.

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