Abstract:

In order to clarify the predation ability and predation regularity of Megalocaria dilatata on bean aphid, the M. dilatata collected in the wild was raised indoors for 2 generations, and then predation of each instar larva, female and male adult was measured. The Holling II disk equation was fitted by the reciprocal method, and the predation characteristics of the M. dilatata were determined. The results showed that the predation amount of M. dilatata increased with the age of M. dilatata. When N→∞, the maximum predation of the 1st to 4th instars larvae, female and male adults on the bean aphid within 1 day were 30.1628, 158.7003, 556.3928, 988.1128, 841.0084 and 589.4011, respectively. The fitting equation between the predation amount and day age was y=3.9123x^2.2092(R²=0.8093), and the predation amount increased exponentially with the increase of day age. The fitting equations of predation and day age of female and male adults were y=0.9453x²-28.274x+827.44(R²=0.456) and y=0.8762x²-31.511x+635.38 (R²=0.7188), respectively, and predation amount of female and male adults decreased gradually with the increase of day age.

Key words: Megalocaria dilatata, bean aphid, predation, natural enemy, biological control