Laboratory tests against banana weevil borer suspected of being resistant to dieldrin

Abstract

Preliminary laboratory tests in which suspected dieldrin-resistant Cosmopolites sordidus were confined on soil treated with 0.05% and 0.1% dieldrin at 1 ml/4700 mm2 (equivalent to the standard field recommendation of 1 pint/stool of radius 3 ft) indicated that they were not resistant. This was confirmed by the results of a micro-drop insecticide test comparing the suspected dieldrin-resistant and a known susceptible population of banana weevil borers. ADDITIONAL ABSTRACT: Control of Cosmopolites sordidus (Germ.) on banana by means of dieldrin had become difficult in one plantation in Queensland, Australia, and it was suspected that the weevil had become resistant to the insecticide. It was shown in laboratory tests that this was not the case.