[Effects of wheat planted adjacent to rape on the major pests and their natural enemies in wheat field].

Based on the dynamic analysis of insect community structure characteristics, an investigation was conducted on the composition, abundance, and stability of wheat aphids and their major natural enemies in the wheat field adjacent to rape field in Handan City, Hebei Province in 2008-2009. The wheat and rape fields had the similar composition of insect communities. The main pests were aphids, their predatory natural enemies included ladybirds, green lacewings, spiders, and hover flies, and their parasitic natural enemies were wasps. In 2008-2009, the composition of insect communities in the wheat and rape fields had definite changes, but the common features were the lowest abundance of aphids and the highest abundance of predatory and parasitic natural enemies in wheat field adjacent to rape field. The insect community, aphid sub-community, and predatory natural enemy' s sub-community had a high stability in the wheat field adjacent to rape field and a low stability far from the rape field, suggesting that planting wheat adjacent to rape could effectively protect and make use of the natural enemies and promote their control ability on wheat aphids in wheat field.