Sublethal contaminant exposure alters behavior in a common insect: Important implications for trophic transfer

Abstract

This study examined the effects of sub-lethal exposure of the ubiquitous pesticide malathion on the behavior of the model orthopteran species, the house cricket (Acheta domesticus). Increasing concentrations of malathion caused male crickets to increase periods of non-directional movement, such as twitching and grooming, directional movement, and to seek out shelter less. These are all behavioral alterations that may increase the cricket's chances of being preyed upon, and thus have the potential for serious ecological consequences through trophic transfer. This study also revealed that female crickets appeared to be less affected by malathion than their male conspecifics, indicating a potential sex-bias in both susceptibility and possible predator attack.

Keywords:

• Predator
• house cricket
• Acheta domesticus
• malathion
• behavior

Acknowledgments

We thank Noldus Information Technology Inc. for technical assistance with use of the EthoVision XT software. We also thank Drs. E. Evans, B. H. Aukema, and the Utah State University Herpetology Group for providing valuable comments on an earlier version of this manuscript. Funding for this research was provided by the USU Department of Biology and by a Natural Sciences and Engineering Research Council of Canada (NSERC) award to GRH.