Rearing Dipha aphidivora, the pyralid predator of sugarcane woolly aphid Ceratovacuna lanigera, on its frozen host may be unfeasible

Abstract

In Petri plate tests, neonate or third to fourth instar larvae of the predator Dipha aphidivora Meyrick (Lepidoptera: Pyralidae) were offered its host Ceratovacuna lanigera Zehntner (Homoptera: Aphididae), the woolly aphid of sugarcane, frozen and stored at −4°C, and thawed at room temperature before releasing the predator. In preliminary tests, neonate and grown-up larvae built webs, fed on aphids, pupated and emerged as adults. In two tests with neonate larvae, adult emergence was 45.5 and 80.0% in 17–21 days. The predator moths laid eggs on white coarse filter paper strips but not on hard paper strips of different colors placed in oviposition cages. Egg-laden filter paper or leaf bits placed in Petri plates with frozen aphids showed hatching but larvae did not survive long. Poor survival of neonate larvae in several additional tests with fresh or one-year old frozen aphid indicated that the method may not be useful for long-term rearing of the predator. Short-term survival of grown-up larvae on frozen aphid may enable the use of the latter as food for predator larvae in transit.