Effect of Bt-Maize on Epigeic Spiders (Araneae) and Harvestmen(Opiliones)

The effect of two strategies, used to control Ostrinia nubialis, on the abundance and diversity of epigeic spiders and harvestmen in maize was monitored. The two strategies were (1) transgenic insectresistant maize, and (2) biological control by Trichogramma wasps on an isogenic maize hybrid. They were compared a conventional system (isogenic maize hybrid), which was taken as the control. The investigation was performed at two localities (Ivanovice na Hane and Prague) in the Czech Republic from 2002 to 2004. Spiders (Araneae) and harvestmen (Opiliones) were collected by means of pitfall traps. We found that the annual abundance diversity of arachnids on plots with the two strategies were not significantly different from a conventional sys-tem.