Response of boll weevil (Coleoptera: Curculionidae) to insecticides applied to different body parts. (134)

Abstract

A test was conducted to determine the response of the boll weevil (Anthonomus grandis Boheman) when the insecticides azinphosmethyl and methyl parathion were applied to the dorsum of the thorax, the tarsus of the front leg, and the orifice at the tip of the proboscis of male and female weevils. Male and female boll weevils showed a greater susceptibility when their proboscis was treated with azinphosmethyl. When males and females were treated on the same body parts with either azinphosmethyl or methyl parathion, no significant differences were observed. This means that a median lethal dose will kill male and female weevils equally, irrespective of the point of contact, i.e., the dorsum of the thorax, the tip of the proboscis, or the tarsus of one leg.