Predation efficacy of Harmonia axyridis on two species of Chaitophoridae and control effect in field
To determine the predation effect and biological control potential of Harmonia axyridis against Periphyllus kuwanaii and Periphyllus koelreuteria,the predatory functional responses and searching effects of different instar larvae of H.axyridis on the two species of aphids were tested in laboratory,and the control experiments on the two species of aphid were carried out by releasing H.axyridis adults in field.The results showed that the predation number of H.axyridis increased gradually with the increase of density of P.kuwanaii and P.koelreuteria.The predation functional responses of H.axyridis against the aphids conformed to the Holling II disc equation.The 4th-instar larvae of H.axyridis had the highest predation capacity to P.kuwanaii and P.koelreuteria,with a/Th for 259.46 and 158.94 individuals,and with 1/Th for 227.80 and 132.89 individuals per day,respectively.The searching effect of H.axyridis on the two species of aphids was negatively correlated with prey density,while the older larvae of H.axyridis exhibited higher searching effects on P.kuwanaii and P.koelreuteria,and the larger the instar,the higher the search effect.H.axyridis had strong ability to control P.kuwanaii in field,and could be used for the control practice of P.kuwanaii.
万方数据
维普
