Cydalima perspectalis Walker (Lepidoptera: Crambidae) to potential biological control agents Neem (NeemAzal ?-T/S) and entomopathogenic nematodes (Nemastar ?) assessed in laboratory bioassays and field trials]]>

摘要

The Box tree pyralid Cydalima perspectalis Walker (Lepidoptera: Crambidae) is one of the accidentally introduced organisms that became invasive and established in Europe within a few years. Thus, eco-friendly preparations are required, which should be accessible, affordable, easy usable and suitable for the application in private and public areas. Therefore, the effects of the plant extract formulation NeemAzal_(?)-T/S (active ingredient Azadirachtin A) and the commercial preparation Nemastar_(?)(entomopathogenic nematode species Steinernema carpocapsae ) were investigated on C. perspectalis larvae in laboratory bioassays and field trials. When NeemAzal_(?)-T/S-treated leaf discs were consumed by larvae in the laboratory, a significant effect on mortality and feeding activity was noted after 14?days of exposure. At this time, 47–62% of the larvae had already died and less than 10% of larvae were still feeding. Application of different S. carpocapsae suspensions (10–200 EPN/100?μl, i.e. per larva) demonstrated a high susceptibility of both tested larval instars (2nd: 10–75% and 4th: 45–100% mortality). In field trials neither the application of Nemastar_(?)nor the use of NeemAzal_(?)-T/S caused mortality rates comparable to those generated by the treatment with plant protection products based on Bacillus thuringiensis . In conclusion, there is a higher variability in terms of the effects of the investigated agents compared to the constant effectiveness of B. thuringiensis . But their use would be possible if individual feeding damage and proper surveillance will be considered in order to be capable of repeating the application timely and a combination with further measures ought to take place.