龟纹瓢虫对柑橘木虱的捕食功能反应及猎物偏好性

为评估龟纹瓢虫Propylea japonica对柑橘木虱Diaphorina citri的生物防治潜能，在实验室条件下测定龟纹瓢虫1~4龄幼虫和成虫对柑橘木虱5龄若虫的捕食功能反应、搜寻效应、自身密度干扰反应以及捕食偏好性。结果表明，龟纹瓢虫1~4龄幼虫和成虫对柑橘木虱5龄若虫的捕食功能反应均符合Holling II型功能反应类型，其各虫态龟纹瓢虫的瞬时攻击率分别为0.313、0.610、0.234、0.585和0.675，处理时间分别为0.088、0.077、0.013、0.008和0.016 d，龟纹瓢虫4龄幼虫对柑橘木虱5龄若虫的捕食能力最大，为73.125，龟纹瓢虫成虫、3龄幼虫、2龄幼虫、1龄幼虫次之，捕食能力分别为42.188、18.000、7.922和3.557。各虫态龟纹瓢虫对柑橘木虱5龄若虫的搜寻效应随柑橘木虱5龄若虫密度升高而下降；在柑橘木虱5龄若虫密度一定的条件下，各虫态龟纹瓢虫对柑橘木虱5龄若虫的捕食率随自身密度升高而下降，其自身密度干扰方程为E=0.421P^-0.52；当柑橘木虱5龄若虫和豆蚜Aphis craccivora 4龄若虫2种猎物共存时，龟纹瓢虫成虫对其食物选择性指数均小于1，表明龟纹瓢虫成虫对这2种猎物无捕食偏好性。表明龟纹瓢虫对柑橘木虱5龄若虫有较强的防控潜能。

Functional response and predation preference of ladybeetle Propylea japonica to Asian citrus psyllid Diaphorina citri

In order to assess the biological control potential of ladybeetle Propylea japonica to Asian citrus psyllid Diaphorina citri, the predation effect, searching efficiency, intraspecific interference and predation preference of P. japonica to the 5th instar nymph of D. citri were studied under laboratory conditions. The results showed that the functional response of the 1st-4th instar larvae and adults of P. japonica to the 5th instar nymph of D. citri fitted well with the Holling II model, and their instant attack rates to the prey were 0.313, 0.610, 0.234, 0.585 and 0.675, and their handling times were 0.088, 0.077, 0.013, 0.008 and 0.016 d, respectively. The predation capacity of the 4th instar larvae of P. japonica to the 5th instar nymph of D. citri was the strongest, which was 73.125, followed by the adults, the 3rd, 2nd and 1st instar larvae (42.188, 18.000, 7.922 and 3.557, respectively). The searching efficiency of P. japonica to D. citri decreased with increasing prey density. Under the conditions of certain density of the 5th instar nymph of D. citri, the predation rate of P. japonica decreased with increasing self-density, and its interference equation was E=0.421P^-0.52. When both the 5th instar nymph of D. citri and the 4th instar nymph of Aphis craccivora were available, the food selectivity index of P. japonica was less than one, indicating that P. japonica had no predation preference to these two prey species. This study suggested that P. japonica has strong control potential against the 5th instar nymph of D. citri.