One of Britain’s bulkiest beetles, the 3-cm-long cockchafer can be heard and seen buzzing and bumping against light fittings and window panes (more commonly in the south) from late April to July.
Until pesticides started controlling them in the Twentieth Century, cockchafers were a serious agricultural pest. The grubs (sometimes called rookworms as they are prized by corvids) can devastate cereal crops. The adults eat leaves and flowers.
In 1320, an Avignon court sentenced cockchafers to exile in a special reserve – the beetles did not comply. In 1574, cockchafers emerged in such numbers in the Severn valley that the volume of carcasses disabled watermills.
Stingless in the tail
The intimidating sharp point at the tip of a cockchafer’s abdomen is not a sting, but a pygidium – used by females to push their eggs deep into the soil.
The cockchafer is sometimes known as the doodlebug. Because of the buzz of its flight, this nickname was used for Germany’s V-1 flying bomb in World War II.
It spends most of its three- to four-year life-cycle underground as a larva eating roots, pupating after three summers. Adults emerge before winter, but stay buried until spring.
Physicist Nikola Tesla used four cockchafers to power a motor as a boy.