Changes in the population density of the horse-chestnut leafminer, Cameraria ohridella and of its parasitoid community at Hédervár during 7 consecutive years (1998-2004)

Abstract

Studies available up to now usually report changes in populations of Camel-cola ohridella and its parasitoids in a period of 3 years or shorter. Due to the limited duration of investigations, no tendencies of changes could be disclosed and, according to the general idea, the infestation level of the horse-chestnut leafminer and the rates of parasitism do not change significantly. Based on our examinations carried out throughout 7 consecutive years we suggest that the infestation level of C. ohridella is generally decreasing and the rate of parasitism is increasing. A possible adaptation of the parasitoids to this new host is showed on the changes of parasitism. In contradiction with earlier studies, authors assume that a partially stable permanent parasitoid community is being developed around the horse-chestnut leafminer. Proportions of adult moths and parasitoids hatched in the same year of sampling or the next year were determined.

Keywords

• adaptation
• Cameraria ohridella
• horse-chestnut leafminer
• parasitism
• parasitoid community