K. Gopalakrishna Pillai

Glasshouse, Greenhouse and Polyhouse Crops

In protected environments, mealybugs Pseudococcus longispinus, P. viburni, Planococcus citri, Phenacoccus gossypii, P. solenopsis, P. madeirensis, Maconellicoccus hirsutus, etc. are serious pests, causing extensive damage to different crops. Mealybugs being the most difficult to control pest, and monitoring, sanitation and regular application of insecticides are the most important elements of their control. Insecticidal soaps, horticultural oils, insect pathogenic fungi, insect growth regulators and systemic insecticides in the crawler stage are effective in management. Augumentative releases of parasitoids like Anagyrus psedococci, Leptomastix dactylopii, Aenasius bombawalei and predator, Cryptolaemus montrouzieri are promising alternatives to chemical control.

Host-age-dependent parasitism and reproductive success of Apanteles stantoni (Hymenoptera: Braconidae), a larval parasitoid of Diaphania indica (Lepidoptera: Pyralidae)

ABSTRACT The relative suitability of five instars of Diaphania indica (Saunders) (Lepidoptera: Pyralidae) as a substrate for the development of a larval parasitoid, Apanteles stantoni Ashmead (Hymenoptera: Braconidae), was investigated. Maximum parasitism (22.25 ± 1.21%) under laboratory conditions was observed in the early larval instars. The highest parasitoid emergence was recorded from the second (86.07 ± 0.70%) and third (98.93 ± 0.72%) instar larvae of D. indica, and that from the first larvae was 71.43 ± 1.18%. The number of cocoons in each cluster, length and width of single cocoons, percentage emergence, sex ratio and adult longevity of A. stantoni collected from different instars of D. indica were also recorded. These results indicated that the life stage of the host when the parasitoid larvae complete their final instar is particularly important for their development. Therefore, considering the efficiency of parasitism and reproduction, the second-instar larvae of D. indica is the most suitable stage for mass rearing A. stantoni in the laboratory.