cockchafer damage images

The cockchafer Melolontha Melolontha

The May beetle is from the family Scarabaeidae. This beetle species is found in many parts of the world. It has been observed in Europe, Russia and parts of Asia, among others.
The May beetle is usually just a little larger than the June beetle, usually measuring 25-30 millimetres, have a dark head and a brown shield on their back.   

The life cycle of a cockchafer 

The cockchafer has four stages which starts with the egg stage. Depending on the temperature, they hatch after four to six weeks. The ideal temperature for the eggs is between 15 and 20 degrees. After the eggs hatch, they enter the larval stage (grubs), which happens in August and September. These larvae do not cause much (visible) damage yet, as they eat only small particles of the roots. But after these larvae get through the winter and are in the third part of their development, their voraciousness increases enormously. This causes a lot of damage to the turf, for example. This third stage usually lasts for a year, which can cause damage to the crop twice. Finally, pupation to beetle takes place in late June. The cockchafer finally flies out in August and can survive the winter in a so-called pupal chamber. This can be just below the surface, but can also be much deeper, sometimes up to a metre deep. In the months of April and May, when the temperature has remained above 10 degrees for several days and nights, the adult cockchafers fly out again.     

How does the cockchafer reproduce

The entire life cycle of the May beetle takes three years in most countries. In some countries, where temperatures are low, the life cycle can take four years.
In April and May, cockchafers emerge from the ground and start looking for places to feed themselves. This food search usually lasts two weeks after which the females fly back to where they hatched sexually mature. At this spot, they usually lay more than 20 eggs. These eggs are hidden at a depth of about 20 centimetres. While laying these eggs, most female beetles die, but a small proportion survive and repeat the cycle. Thus, when conditions are right, a female can lay more than 40 eggs with all the harmful consequences.   

life cycle grubs in soil June beetle cockchafer

Damage caused by the May beetle

Adult cockchafers cause very little damage. In an exceptional case, a plum tree may fall prey to a cockchafer, but they must be present in large numbers. The greatest damage is caused by the popularly known grubs. These C-shaped larvae feed on the roots of crops. This can occur in various places, including meadows, gardens, but they can also be active in nurseries. A side effect is the fact that by attacking roots, plants become more vulnerable to other diseases. In addition, so-called collateral damage exists as birds and other mammals search for the larvae and overturn the grass to find them.

Get up to 10% discount on pesticides at our partner Biobestrijding

green bull biological control(1)

Receive a discount code directly in your mailbox

After you receive the code, you can place an order directly in the webshop.

There is a link in the mail. Good luck with biological control >

You have successfully registered. Now go to your mailbox.