双带盘瓢虫对夹竹桃蚜的捕食特性及猎物偏好OA

The oleander aphid,Aphis nerii,is an important pest of common landscaping plants,including milkweed(Asclepias curassavica)and oleander(Nerium indicum).Coelophora biplagiata is an important predatory natural enemy in agriculture and forestry.To clarify the predatory performance of C.biplagiata against A.nerii and its potential for biological control,laboratory studies were conducted to determine the functional response,intraspecific interference,predation capacity at different temperatures,and prey preference of C.biplagiata toward A.nerii.The results showed that the functional response of C.biplagiata to A.nerii conformed to the Holling Ⅱ model.The instantaneous attack rates of the 1st-4th instar larvae and female/male adults were 0.629,1.582,1.157,1.698,1.538 and 1.522,respectively,while the corresponding handling times were 0.115,0.069,0.020,0.010,0.008 and 0.016 days.The theoretical maximum daily predation rates were 8.696,14.493,50.000,100.000,125.000 and 62.500 individuals,respectively.Predation increased with larval instar,and female adults consumed significantly more aphids than male adults.The searching efficiency decreased with increasing prey density.Under constant A.nerii density,the predation efficiency of C.biplagiata decreased with increasing predator density,accompanied by intensified competition.At temperatures of 20,25,30,35℃ and 40℃,the predation rates of C.biplagiata female adults on A.nerii were 50.333,68.500,77.833,75.833 and 10.333 individuals,respectively.Predation increased initially and then decreased with rising temperature,and no significant difference was observed between predation rates at 30℃ and 35℃(P=0.519).Compared with A.nerii,C.biplagiata exhibited a preference for feeding on Aphis craccivora.In conclusion,C.biplagiata can prey on A.nerii,but its predation is strongly influenced by environmental temperature.