Control of cockchafer Melolontha spp. grubs – a review of methods

The paper presents a review of information on control measures used to prevent damages due to cockchafer Melolontha spp. grubs in European countries including Poland. There are described the methods used at times when mechanical and chemical treatments were applied as well as those under advanced research. In the past, cockchafer grubs were manually removed from plowed soils. Later on, chemical pest control commenced in plant protection practice, and a range of insecticides were either spotted directly onto plants or applied into planting rows, otherwise an entire planting area was treated. In that case, powder or granular insecticide formulations were mixed with upper soil layers, but liquid insecticides were poured into the soil around seedlings. The active substance of initial plant protection products used in Poland to control cockchafer grubs was lindane (organochlorine neurotoxin), which showed pretty high efficacy. Nevertheless, organochlorine products must have been withdrawn from the market and less damaging to the environment pesticides (organophosphates and carbamates) were recommended for use in forest protection against cockchafer grubs. As a result of progressive restrictions concerning application of chemicals into forest environment, alternate solutions have been sought, e.g. biological methods of cockchafer grub control have been tested. Up to date studies showed insecticidal properties of bacteria, fungi and nematodes. However, even though the knowledge and awareness of practitioners have raised with time, the problem of cockchafer grub populations damaging forest crops has not yet been solved and seems to be more and more difficult to overcome.