EVALUATION OF BACULOVIRUS PHTHORIMAEA VG IN LARVAE OF THE TUBER MOTH PHTHORIMAEA OPERCULELLA (ZELLER)

Abstract

Larva of Phthorimaea operculella (Zeller) was exposed to seven con­centrations of a granulosis virus Bacu­lovirus phthorimaea, which varied from 4,9 x 10² to 9,9 x 10⁹ capsules/ ml. Concentrations were tested using a complete randomized design with four replications. In each replication 25 third-instar larvae (9 days-old at 21°C) were used. The virus was pathogenic to larvae of P. operculella, mortality varied from 39,2% to 98,7°/o for the lower and higher concentrations test­ed. The lethal medium time varied inversely with the concentration, this time was 5,2 days to the highest con­centration and 16,2 days to the lowest concentration. The lethal medium con­centration was 5,6 x 10³ capsules/ml. There were no significant differences (P = 0,05) in virus susceptibility be­tween the Antioquia and Cundinamar­ca insect populations.