Cockchafer

The cockchafer (colloquially called May bug, mitchamador,^[1] billy witch,^[2] or spang beetle,^[2] particularly in East Anglia) is a European beetle of the genus Melolontha, in the family Scarabaeidae.

Once abundant throughout Europe and a major pest in the periodical years of "mass flight", it had been nearly eradicated in the middle of the 20th century through extensive use of pesticides and has even been locally exterminated in many regions. However, since an increase in regulation of pest control beginning in the 1980s, its numbers have started to grow again.

Taxonomy

There are three species of European cockchafers:

• The common cockchafer, Melolontha melolontha
• The forest cockchafer, Melolontha hippocastani
• The large cockchafer, Melolontha pectoralis, which is very rare and occurs only in south-western Germany.

Description

Imagines (adults) of the common cockchafer reach sizes of 25–30 mm; the forest cockchafer is a bit smaller (20–25 mm). The two species can best be distinguished by the form of their pygidium (the back end): it is long and slender in the common cockchafer, but shorter and knob-shaped at the end in the forest cockchafer. Both have a brown colour. Male cockchafers have seven "leaves" on their antennae, whereas the females have only six.

The species M. pectoralis looks similar, but its pygidium is rounded. The cockchafer should not be confused with the similar European chafer (Rhizotrogus majalis), which has a completely different life cycle, nor with the June beetles (Phyllophaga spp.), which are native to North America, nor with the summer chafer (or "European June bug", Amphimallon solstitiale), which emerges in June and has a two-year life cycle. (All of these are Scarabaeidae, have white grubs, and are turf pests.)

Life cycle

Adults appear at the end of April or in May and live for about five to seven weeks. After about two weeks, the female begins laying eggs, which she buries about 10 to 20 cm deep in the earth. She may do this several times until she has laid between 60 and 80 eggs. The common cockchafer lays its eggs in fields, whereas the Forest Cockchafer stays in the vicinity of the trees. The preferred food for adults is oak leaves, but they will also feed on conifer needles.

The larvae, known as "white grubs" or "chafer grubs", hatch after four to six weeks. They feed on plant roots, for instance potato roots. The grubs develop in the earth for three to four years, in colder climates even five years, and grow continually to a size of about 4–5 cm, before they pupate in early autumn and develop into an adult cockchafer in six weeks.

The cockchafer overwinters in the earth at depths between 20 and 100 cm. They work their way to the surface only in spring.

Because of their long development time as larvae, cockchafers appear in a cycle of every three or four years; the years vary from region to region. There is a larger cycle of around 30 years superimposed, in which they occur (or rather, used to occur) in unusually high numbers (10000s).

Pest control and history

Both the grubs and the imagines have a voracious appetite and thus have been and sometimes continue to be a major problem in agriculture and forestry. In the pre-industrialized era, the main mechanism to control their numbers was to collect and kill the adult beetles, thereby interrupting the cycle. They were once very abundant: in 1911, more than 20 million individuals were collected in 18 km² of forest ^{[citation needed]}.

Collecting adults was an only moderately successful method. In the Middle Ages, pest control was rare, and people had no effective means to protect their harvest. This gave rise to events that seem bizarre from a modern perspective. In 1320, for instance, cockchafers were brought to court in Avignon and sentenced to withdraw within three days onto a specially designated area, otherwise they would be outlawed. Subsequently since they failed to comply, they were collected and killed. (Similar animal trials also occurred for many other animals in the Middle Ages.)^[3]

In some areas and times, cockchafers were even served as food. A 19th century recipe from France for cockchafer soup reads: "roast one pound of cockchafers without wings and legs in sizzling butter, then cook them in a chicken soup, add some veal liver and serve with chives on a toast". And a German newspaper from Fulda from the 1920s tells of students eating sugar-coated cockchafers. A cockchafer stew is referred to in W.G. Sebald's novel The Emigrants.

Only with the modernization of agriculture in the 20th century and the invention of chemical pesticides did it become possible to effectively combat the cockchafer. Combined with the transformation of many pastures into agricultural land, this has resulted in a decrease of the cockchafer to near-extinction in some areas in Europe in the 1970s. Since then, agriculture has generally reduced its use of pesticides. Because of environmental and public health concerns (pesticides may enter the food chain and thus also the human body) many chemical pesticides have been phased out in the European Union and worldwide. In recent years, the cockchafer's numbers have been increasing again, causing damage to over 1,000 km² of land all over Europe. At present, no chemical pesticides are approved for use against cockchafers, and only biological measures are utilised for control: for instance, pathogenic fungi or nematodes that kill the grubs are applied to the soil.

Cultural references

Children since antiquity have played with cockchafers. In ancient Greece, boys caught the insect, tied a linen thread to its feet and set it free, amusing themselves to watch it fly in spirals. English boys in Victorian times played a very similar game by sticking a pin through one of its wings.^[4] Nikola Tesla recalls that as a child he made one of his first "inventions" — an "engine" made by harnessing four cockchafers in this fashion.^[5]

The cockchafer is featured in a German children's rhyme similar to the English Ladybird, Ladybird:

Maikäfer flieg... Dein Vater ist im Krieg Deine Mutter ist in Pommerland Pommerland ist abgebrannt Maikäfer flieg!

Cockchafer fly... Your father is at war Your mother is in Pomerania Pomerania is burned to the ground Cockchafer fly!

The verse dates back to the Thirty Years' War in the first half of the 17th Century, in which Pomerania was pillaged and suffered heavily. Since World War II, it is associated in Germany also with the closing months of that war, when Russian troops advanced into Eastern Germany.

The cockchafer figures in a notable Polish tongue-twister: W Szczebrzeszynie chrząszcz brzmi w trzcinie... "In Szczebrzeszyn the cockchafer buzzes in the reeds, and therefore Szczebrzeszyn is famous." ^[6]

The last name of the colorful Soviet politician Nikita Khruschev is derived from the Russian word for cockchafer, "khrushch".

Cockchafers also play a part in Hans Christian Andersen's version of Thumbelina (1835).^[7]

The cockchafer was the basis for the "fifth trick" in the well-known illustrated German book Max and Moritz dating from 1865.

In the novel The Siege of Krishnapur (1973.) by J.G. Farrell, the character Lucy rips off her clothes and faints upon being covered in a swarm of cockchafers.

In the novel The Emigrants (1992) by W.G. Sebald, in the section entitled "Paul Bereyter," the narrator sits in the back of Bereyter's class at school with Fritz Binswanger near a cockchafer display case which includes "a pair of cockchafers...a clutch of eggs, a pupa and a larva, and in the upper portion, cockchafers were hatching, flying, and eating the leaves of apple trees." The boys are inspired to study cockchafers because of the case, and finally they make and eat a cockchafer stew.

There have been five Royal Navy ships named HMS Cockchafer.

The binomial nomenclature Melolontha melolontha was mentioned in an episode of Bones (2005) entitled "The Tough Man in the Tender Chicken": as Drs. Brennan and Hodgins enter the lab, Dr. Hodgins said he came in (to the lab) early to see if his Melolontha melolontha had hatched.

References

The Italian, specifically Neapolitan, collection of stories Il Pentamerone of Giambattista Basile (in its English translation by Norman M. Penzer from Benedetto Croce's Italian) contains a tale on Day 3, Night 5: "The Cockchafer, Mouse and Grasshopper".

External links

Wikimedia Commons has media related to Melolontha melolontha.

Wikispecies has information related to: Cockchafer

• Cockchafers and other chafers
• Der Maikäfer, from the Senckenberg Museum in Frankfurt (German)
• Images (German)
• Pests: The Cockchafer with links to images and French and English text.
• Biological Pest Control Research and risk assessment on the biological control of insect pests in the EU.
• Fact sheet on some other chafers that also have white grubs and are turf pests.
• Elegy by German folksinger Reinhard Mey on the vanished cockchafers of days gone by: Es gibt keine Maikäfer mehr
• Maikäfer flieg