EFFECT OF A GRANULOSIS-VIRUS ON PLODIA-INTERPUNCTELLA (HUBNER) (LEPIDOPTERA, PYRALIDAE) INFESTATIONS OCCURRING IN STORED RAISINS

Neonate larvae of Plodia interpunctella (Hübner) were exposed to 5 different concentrations of a granulosis virus (GV) on raisins; the estimated LC50 was between 1 × 103 and 1 × 104capsules/ml of suspension. Raisins treated with 1 × 108capsules/ml GV suspension were protected from P. interpunctella infestation for at least four months under normal storage conditions. The treated raisins retained the GV inoculum after 5 min of water washing. Field-run raisins treated with GV in two separate tests (14 and 9 weeks) reduced moth populations by 95.2% and 96.9%. Treatment with GV of processed raisins prior to packaging and of the packages themselves (containing raisins) reduced moth populations over a six-month period by 75.5% and 33.2%, respectively. © 1979.