Effect of body size of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) on mating success

Abstract

Various-sized females (3 to 8 mg) were paired with various-sized males (3 to 7 mg) in a glass tube (30 mm in diameter, 200 mm in length) for a period of 2 days. Pupal weight was used as an index of adult size. When the difference in body weight between a female and a male was 0 to 2 mg, a large proportion of female (75.2 to 92.7%) succeeded in mating and laid fertilized eggs. However, when the difference ex-ceeded 3 mg, the probability of a successful mating decreased by 50. 0 to 76.9%. This suggests that 3 mg of inter-sexual difference in weight has some ill effects on mating.