Influence of heavy metal contamination on urban natural enemies and biological control.

Urban agriculture is increasing worldwide. A history of contamination within urban landscapes may negatively impact the biota necessary for sustainable crop production, including arthropod natural enemies. This investigation revealed that heavy metal contamination can influence the composition of natural enemy communities and exposure can have reproductive, developmental, immunological and behavioral impacts on predators and parasitoids. Natural enemies exposed to heavy metals typically live shorter lives, take longer to develop and exhibit a reduced reproductive potential. Further, they may incur significant energy costs though the production of detoxification enzymes. This is a new and relatively unexplored area for biological control research, with important implications for our understanding of urban agricultural food web interactions.