Intraguild predation of Phenacoccus manihoti parasitoid Anagyrus lopezi by two mealybug predators, Cryptolaemus montrouzieri and Plesiochrysa ramburi

Abstract

Anagyrus lopezi is a specialist parasitoid was introduced to Indonesia in 2014 to control cassava mealybug, Phenacoccus manihoti. Plesiochrysa ramburi and Cryptolaemus montrouzieri are generalist predator insects associated with the mealybug. Intraguild predation is a crucial competition in an insect community. The study objective was to investigate interference of both predators on healthy mealybug (unparasitized) or parasitized mealybug by A. lopezi (mealybug which containing parasitoid larvae 1-, 3-, 8-, and 14-day old). Experiments were carried out in a non-choice test (served only one unparasitized or parasitized mealybug of a specific parasitoid age) and choice test (unparasitized and parasitized mealybug of a specific parasitoid age together) in laboratory under controlled environmental conditions. Both of predators species able to fed on both unparasitized and parasitized mealybugs of three different age (1-, 3-, and 8- day-old), but both predators discriminated against mealybug were parasitized 14-day old (hardened mummies). Interaction between parasitoid of A. lopezi and both predators showed antagonistic interaction type. We recommended A. lopezi should be released in field at the beginning of the time when the population of the mealybug is still low and could be continued with the predators release when the mealybug population is high.