Zur Biologie und Populationsentwicklung der eingeschleppten Rosskastanien- Miniermotte, Cameraria ohridella

Wien

1997

8 Lit. Ang.

Unselbständiges Werk

12531

200051902

The introduced horse-chestnut leafminer, Cameraria ohridella, has 3 overlapping generations, with adults appearing mostly in May, July, and September. The egg stage lasts from 2 to 3 weeks, the feeding period, on average, 4 weeks, and the pupal stage in the mine about 2 weeks, but at least 6 months in the partial 3rd generation overwintering in the litter. Infestations of old and young trees in the Vienna City forests, streets and parks have been excessive during the last 5 years, with 100% defoliation and leaf fall occuring already at the end of the 2nd generation in August. Possibly due to this food shortage, a few mines of the 3rd generation have appeared on sycamore (Acer pseudoplatanus). High mortality rates due to intraspecific competition for space and food occurred during all 3 generations, intensified by the simultaneous presence of a fungus disease (Guignardia aesculi) damaging the leaves. Rates of predation and parasitism have so far been negligible.