Abstract:

In order to clarify the effect of different proportions of aphid feeding on the oviposition characteristics of Harmonia axyridis, and lay a theoretical foundation for the follow-up study of artificial diet of H. axyridis, five treatments were designed in this experiment, which were fed with aphid reduction of 100%, 75%, 50%, 25% and 0%, namely group A, B, C, D and E. Group A was fed with artificial diet and group E was fed with aphid. The quantity, hatching rate, mortality and location of oviposition under each treatment were recorded in this experiment. The results showed that there was no significant difference in the amount of eggs laid between group D and group E, the amount of eggs laid by ladybugs fed with aphid reduction of 50% or more was significantly lower than that of the control group. The number of collectable egg masses and egg grains in each treatment was significantly higher than that of non-collectable egg masses and egg grains, and the number of collectable eggs in group A, B and C was significantly lower than that in group E. The oviposition amount of ladybugs in each treatment fluctuated significantly with time, with an average peak of 4 days. The hatching rate of group B, C and D was slightly higher than that of group E, but there was no significant difference. The mortality rate of females was generally higher than that of males, the mortality rate from high to low was Group E>A>B>C>D. This study showed that the reduction of aphid feeding by 25% did not reduce the quantity of effective oviposition of H. axyridis, and the reduction of aphid feeding by more than 50% significantly reduced the quantity of effective oviposition of H. axyridis, thus clarifying the effects of different proportions of aphid reduction feeding on the oviposition characteristics of H. axyridis.

Key words: aphid, Harmonia axyridis, artificial feed, oviposition quantity, biological control