Fitness of five Aphids gossypii Glover populations collected from various hosts, including three overwintering hosts, zanthoxylum (Zanthoxylum bungeanum Maxim), pomegranate (Punica granatum L.), hibisucus (Hibisucus Syriacus L.), and two summer hosts, cotton(Gossypium arboreum L.) and cucumber(Cucumis sativus L.), was studied on cotton and cucumber by laboratory host plant transplantation experiment. The results showed that both the dwell and reproductive rate to cotton of A. gossypii collected from zanthoxylum, hibisucus and cotton were significantly higher than those to cucumber, but these two index to cotton were lower than to cucumber when A. gossypii was collected from cucumber. The reproductive rate of aphids came from pomegranate was lower on cotton than on cucumber, but the dwell rate was equal.
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