Strengthening biological control of cotton aphid (Aphis gossypii) in northern Xinjiang, China

I studied the effects of diversification measures on cotton aphid and its natural enemies in cotton. I first determined which habitats in cotton growing landscapes in northern Xinjiang provide foraging and reproduction opportunity for natural enemies that may later spill over to cotton. Then I looked at the effect of intercropping cotton with wheat or maize on cotton aphids and their enemies in cotton. Third, I studied how enemies spilled over to cotton fields from adjacent fields with wheat or maize. I found that this spillover resulted in enhanced predation activity and lower cotton aphid densities in cotton. Finally, I studied the effect of the whole landscape on cotton aphids and their enemies in cotton fields.

Habitats that support natural enemy reproduction and foraging, such as wheat, led to spillover of those enemies to cotton at all studied scales (intercrop, adjacent fields, landscape). This suggests that interspersing these source habitats narrowly with cotton will improve biological control of cotton aphid.