Influences Of Three Aphid Species On Ecological Characteristics Of Adonia Variegata (Goeze)

Influence of three aphid species on development, survival and reproduction of Adonia variegata(Goeze)was investigated at 25±1℃in the laboratory. The results indicated that there were significant differences in the durations of different developmental stages, survival, generation time, longevity, weight and fecundity of adults when reared on these three species of aphids, respectively. The generation time, adult longevity, oviposition duration, adult weight, fecundity and intrinsic rate of increase (rm) were 22.7d, 38.6d, 16.2d, 6.2mg, 149.7 and 0.0725, respectively, when reared on Macrosiphum avenae. They were 24.6d, 31.5d, 20.1d, 6.0mg, 100.5 and 0.0441, respectively, when reared on Hyalopterus amygdale. They were 28.6d, 25.5d, 6.2d, 4.2mg, 45.3 and 0.0408, respectively, when reared on Aphis gossypii. The survival curves fell into Deevey I. A. variegata displayed a decreasing preference on the three species of aphids in the following order: M. avenae, H. amygdale and A. gossypii.The functional responses that Adonia variegata (Goeze) preyed on M. avenae, H. amygdale and A. gossypii were tested . The results indicated the models of functional responses of the ladybird to these three species of aphids belong to HollingⅡ. With the increase of the density of all the aphids, the preying quantity of Adonia variegata(Goeze)increased gradually in a certain range.The preying time of Adonia variegata(Goeze)on per aphid displayed a decreasing preference on the three species of aphids in the following order: H. amygdale , M. avenae and A. gossypii. On the other hand , the instantaneous preying rate showed the contrary trend. The temperature also affected the preying quantity of Adonia variegata(Goeze).The location and selectivety of Adonia variegata (Goeze)adults to M. avenae, H. amygdale and A. gossypii were investigated in Y-shape olfaction instrument.The result showed that wheat , peach and cucumber did not produce plant volatiles for attracting Adonia variegata(Goeze).The volatiles of three species of aphids obviously attracted Adonia variegata(Goeze).The volatiles released by the aphids and the injured plants showed a much strongger attraction to Adonia variegata (Goeze).