Zum Einfluß von Insektiziden auf die Aktivitätsdichte der Laufkäfer (Col., Carabidae) im Winterweizen

Abstract

Investigations on the influence of insecticides on the density of activity of carabid beetles (Col., Carabidae) in winter wheat Experiments to evaluate the side effects of insecticides on several species of carabid beetles were carried out in winter wheat fields of Halle/S. area during the years 1986 to 1988. The insecticides Decis (Deltamethrin), Filitox (Methamidophos) and Nurelle-D (Chloropyriphos and Cypermethrin) have been a plicated at the beginning of ear emergence (DC 50) and Bi 58 EC (Dimethoat) at the beginning of milEy ripe of the winter wheat (DC 70). The beetles were catched by pitfall traps. Results of the catches in 1986 to 1988 are separately represented for the most frequent carabid species, Platynus dorsulis (Pont.), Loricera ilicornis (F.), Pterostichus melanarius (Ill.), Poecifus cupreus (L.), Bembidion lumpros (Herbst) anlClivina fossor (L.). The proved insecticides caused in some cases only little reductions of the number of ca tured beetles, but otherwise si nificant diminutions have to be seen. and carafid beetles s ecies. The experiments have been arranged in small plots. Results of small plot experiments have on& value for a short time span after the application date of the insecticides.The com arison of the results ofthe three years often shows dif P erences relating to proved insecticides