Factors Affecting the Use of a Chemosterilising Bait-Station for Control of the Red Bollworm Diparopsis castanea (Hmps)

Abstract

To develop an auto-sterilising device for the red bollworm Diparopsis castanea (Hmps.) a prototype bait-station was used in the laboratory with virgin females as bait which consistently attracted male moths of various ages. The female moths were attractive for at least 8 days. Males sterilised by overnight contact on filter-paper saturated with 0.2% aq. tepa were as responsive to the virgin females as untreated males.

A marker dye technique made it possible to determine whether the males would actively probe on arrival at the bait-station, which was lined with wet filter-paper, and so sterilise themselves, assuming that the water contained a chemosterilant. At 27°C and 70% r.h. and 25°C and 35% r.h. probing did not occur to an appreciable extent until the males were at least 3-4 days old whether or not flight activity had previously occurred. Since both sexes are sexually mature on emergence, it was concluded that the control method tested was unlikely to be effective. The possibilities of alternative sterility methods are discussed.