Once an abundant beetle in temperate Europe, Northern Asia and continental USA, the May Bug is nowadays quite a rare visitor to our gardens. However, after pesticide controls were implemented in last decades, its numbers have started to grow again.
|Melolontha melolontha from EoL - image is under CC BY-NC.|
The May Bug is 20 - 30 mm long beetle belonging to family Scarabaeidae. Female beetles lay 15-30 eggs three times during late spring. The larvae hatch after 4-6 weeks. They live in the soil feeding on roots of grasses and cereals and might be serious pests.
|Melolontha solitaria from Europeana - image is under CC BY-ND of National Museum, Prague.|
The larvae live for about 3-4 years. Pupate adult beetles stay hidden underground hibernating over winter and then fly out collectively. This corresponds to the development of the larvae and thus, adult beetles appear every 3-4 years in large numbers. This happens usually in April or May, which is where the name "May Bug" came from. The adult beetles feed on leaves and flowers of deciduous trees, plants and shrubs but do not tend to be serious pests. They are most likely to be seen in the evenings, often crashing into windows after being atracted by artifical light of human buildings. The beetle produces an alarming loud buzzing noise as it flies, but it is harmless to humans.
The genus Melolontha is also known to palaeontologists as it has been found fosilised. Pictured is a specimen of the Miocene age from the collection of the National Museum, Prague.