May: Cockchafers

One of my abiding memories of early childhood was of my two older sisters screaming “get it out of here” from their respective bedrooms, while I rushed excitedly to find out what beastie had encroached into their hallowed space!

If it was the month of May, then very often it would be a May-bug or to use its proper name, Cockchafer.  These are fairly heavy-duty, and I suppose quite frightening beetles, with shiny brown wings and large antennae resembling the antlers of an Elk, that can come crashing into bedrooms at this time of year, attracted by any light that is on after dark.

These leafy antennae can detect pheromones, enabling males to find females even in the dark! Cockchafer males can easily be distinguished from the females by counting the number of ‘leaves’ on their remarkable antler-like antennae, males sport seven ‘leaves’ while females have only six. The additional 'leaf' carried by the male assists in detecting the pheromone used as reproductive enticement by the female.

These striking beetles are only around for about 6 or 7 weeks, but during this time the female can lay as many as 80 eggs. However, on hatching out, the fat white grubs, with their orangey brown heads, grow very slowly and can live in the soil for 3 or 4 years, growing up to 2 inches in length before pupating and hatching out as an adult beetle.

The grubs are particularly fond of grass and cereal roots, but most plants are susceptible to their voracious appetite; patches of wilting plants giving away the first sign of their presence. If you pull up these plants you will find that they have virtually no roots left, and with a little further investigation in the soil below the plant you will find the culprit, curled in its usual “comma” shape.

It is because of this that Chafer grubs, as they are known, are perhaps more widely recognised as they can be a serious pest. In fact, the word “Chafer” is a Middle English word meaning to “gnaw” and the cock part of the word probably refers to the “maleness” of this robust, antler bearing beetle.  

Because these grubs are fat and juicy they are heavily sought after by a wide range of species and are therefore quite an important part of the food chain. Rooks in particular spend lots of time hunting out such tasty morsels, so much so, that many country folk call the grubs “rook-worms”.

In the past Cockchafers were incredibly abundant and caused major crop failures, but the ploughing up of many old pastures and the introduction of certain pesticides have made them a far less common sight nowadays. 

In the Middle Ages, collecting the adult beetles was really the only way that people could try to control their numbers and protect their crops. In France, this gave rise to events that seem bizarre from a modern-day perspective.

In 1320, Cockchafers were brought to court in Avignon and sentenced to withdraw within three days into a specially designated area, otherwise they would be outlawed. Subsequently, since they failed to comply, they were collected en masse and killed.

Don’t you just love the French!! (I bet they ate them too!)