Investigations on the population ecology and the population control of the Common earwig <em>Forficula auricularia</em> (Linnaeus) in vineyards of the Palatinate

Abstract

The Common earwig has been classified as a beneficial predator in vineyards. Amongst others the insect feeds on grape pests like different tortricids. In recent years within many regions of the viticultural area of the Palatinate the individual densities increased to an extremely high level. Earwigs may cause direct damages such as contamination of the grapes with faeces, eroded berries and transfer of pathogens. The chemical agent 2-methyl-1,4-benzoquinone, released from the abdominal glands while earwigs are menaced and likewise contained in faeces, may have a negative influence on the wine quality. All these facts constitute a quality downslide by winegrowers. The high number of earwigs in the grapes after harvesting causes a negative image by consumers.

This study was carried out to investigate possible relations between the population dynamics of earwigs and specific environmental conditions in vineyards. The main focus of the research project is to test chemical, ecological and biological strategies to reduce the population densities. Another important point of survey was to study the life cycle of earwigs especially in vineyards.

For sampling purposes in the trunk zone a special life trap out of bamboo tubes has been developed. This type of trap showed the highest catch rate of the four trapping types tested. For the monitoring of ground dwelling earwigs pitfall traps were used.