Host stage specific biology of Aenasius arizonensis on cotton mealybug,Phenacoccus solenopsis

ObjectiveThe present research was conducted to understand the influence of Aenasius arizonensis on Phenacoccus solenopsis at different development stages to provide reference for rearing and potential augmentation in bio-logical control of P. solenopsis.MethodIn the host choice based experiment and non-choice based experiment,15 mealybugs of 4 different instar nymphs and 303rd instar larvae and adults of the mealybugs were used as test insects. A pair of A. arizonensis were placed in each cage and survival situation of host and parasitoids were recorded daily.ResultThe results depicted that the highest host stage specific parasitism and mummy formation were recorded for 3rd instar nymph mealybugs under choice and non-choice based experiments, whereas the lowest parasitism was recorded on 2nd instar stage. Longevity of the female observed during the choice and non-choice based experiments were not significantly different from each other(P>0.05). Female A. arizonensis lived for 12.69±0.19 and 13.24±0.40 d when 2nd instar nymphs of the host provided under choice and non-choice based experiments. Similarly,female A. arizonensis lived for 15.51 ± 0.28 and 15.12±0.14 d on 3rd instar nymphs and 15.88±0.25 and 15.75±0.24 d on adult host stage,respectively. The total development period of the parasitoid was greatly varied on different life-stage hosts. The total development period of A. ari-zonensis from egg insertion to adult emergence was the longest when 3rd instar nymphs of P. solenopsis were offered for patriotization,while the shortest time was recorded for 2nd instar nymph mealybugs under choice and non-choice based experiments.ConclusionIt is concluded that the maximum adult emergence of A. arizonensis was recorded on 3rd instar host stage and minimum on 2nd instar host stage.