Dynamics of fruit fly and borer infestations in relation to their biological control agents and host jackfruit phenology

The project sought to determine basic information gaps toward a sound a sustainable jackfruit pest management system in Eastern Visayas. The 3-year population fluctuations of jackfruit fruit fly significantly varied, with general population peaks observed in May to September, the jackfruit major fruiting season. Six insect parasitoids,three entomopathogens, and two predators were discovered as novel biological control agents of jackfruit fruit fly. A promising braconid wasps, Apanteles sp. was found to preferably attack the second and third instar larvae of the jackfruit crambed fruit borer with an average of 33.5 parasitoids emerging before its death. Complementarily, the lethal concentration (LC50) of metahizium anisopliae SPW isolate and Beauveria Coleop. Co.No. 69 isolate on fruit fly adults were 2.01 x 10E5 and 4.54 x 10 E6 spores/ml, respectively. The former took shorter lethal time (LT50) of 4.97 days than 8.78 days for the latter and are still found infective to fruit fly pupae four weeks after its application in the soil. M.anisopliae could also be transmitted by artificially treated male adults to healthy female adults, whose transmission mechanism is believed to be due to mating and direst contacts between infected and healthy individuals in caged experiment. Moreover, the fungus could infect all fruit fly pupal stages in the soil and still capable of post-emergence infection. The soil around the jackfruit plantation can now be treated with M.anosopliae during the fruiting season to hopefully infect the pupating larvae dropping on the soil surface and/or possibly develop a M. anosopliae laden attractant to contaminate the wild population in the field. A cost-efficient mass production substrate (50% palay and 50% rice bran)for M. anisopliae was developed. Development and application timing of sound pest management interventions and early warning advocacies for jackfruit fruit flies and borers could now be enhanced.