The effect of tau-fluvalinate and lambda-cyhalothrin on two parasitic species of Phradis spp. [Hymenoptera, Ichneumonidae, Tersilochinae]

The effect of two pyrethroid ester insecticides, as well as their concentration, on the insect survival were studied along with the dynamics of the insect intoxication, as dependent on the application rate of the chemicals. The laboratory tarsal plate test, carried out in May 2006, was based on commercial formulations of τ-fluvalinate and λ-cyhalothrin instead of pure a.i. The study aimed at producing practical recommendations about the reduction of the application rate in the chemical protection of the oil seed rape (OSR) against the pod and the stem weevils and against the pollen beetle. The results suggest that the application rate reduction of τ-fluvalinate does not alter considerably the survival of the tested insect parasitoids, whereas in case of λ-cyhalothrin it is accompanied by an increase in the insects`survival

The quantitative changes of ground beetles (Col., Carabidae) in Bt and conventional maize crop in southern Poland

In the southern part of Poland, ground beetle fauna was studied in the first large-scale Bt maize experiment. The aim of this study was to determine the long term impact of the Bt maize cultivar in comparison to conventional plants, on selected non-target arthropods. The DKC 3421 YG cultivar (Bt maize) and the respective isogenic non-Bt varieties (DKC 3420) were cultivated at two locations: (a) Budziszów near Wrocław and in Głuchów near Rzeszów in the south-eastern region of Poland, in the 2008-2010 growing seasons. For comparative analysis, two additional non-Bt cultivars sprayed with a lambda-cyhalotrine insecticide were also included. To monitor population density of surface-active invertebrates of the Carabidae family, eighty pitfall traps were used at each location. The average number of ground beetle populations in the Bt-maize cultivar DKC 3421 YG did not significantly differ from the number of beetles in the conventional ones. Significant differences between the number of beetles occurred on individual dates only. Usually, these differences related to the considerably smaller total number of beetles in the whole replication. Probably, the variation in the number of beetles was caused by climatic factors or the terrain layout, therefore it cannot be related to the cultivar effect