关键词: 梨小食心虫, 蛹重, 繁殖力, 成虫寿命, 幼虫发育

Abstract: 【Aim】 This study aims to investigate the effects of pupal weight of Grapholitha molesta (Busck), associated with nutrition, on the fecundity, oviposition duration, longevity of both male and female adults and the development of larvae of the next generation (F₁). 【Methods】 G. molesta pupae of various weights were reared in the laboratory and sorted into three groups: heavier, medium and lighter groups. After emergence and mating, the fecundity, oviposition duration, and survival of male and female adults were recorded. Before the eggs were hatched, the sizes of eggs were measured; after egg hatching the sizes of newly hatched larvae were measured, and the egg hatchability and the larval duration were observed. 【Results】 Female pupal weight of G. molesta significantly affected the fecundity of adults, and had a positive linear correlation with the number of eggs laid (y=15.505x-59.292) and a linear correlation with the male pupal weight (y=0.823x-0.538). The female pupal weight also had a significant effect on oviposition duration. The peak oviposition period of the lighter pupal weight group appeared 1 d earlier than that of the heavier group. The oviposition duration with the number of eggs laid per female per day greater than 10 was 9-10, 7 and 5-6 d, respectively, for the heavier, the medium and the lighter groups, while the oviposition duration with the number of eggs laid per female per day greater than 5 was 12-13, 9 and 6-7 d, respectively, for the three groups. However, male pupal weight had no obvious effects on adult fecundity and oviposition duration. Moreover, the longevity of adult females emerged from lighter pupae was 2-3 d shorter than that of adult females emerged from the heavier ones. But male pupal weight showed no significant effect on the longevity of adult males. Pupal weight was found to have no statistically significant effects on egg hatchability, sizes of eggs and newly hatched larvae, and the growth and development of F₁ larvae. 【Conclusion】 Female pupal weight of G. molesta has a significant effect on the fecundity and oviposition duration of female adults. With these conclusions in mind, we should consider the weight of moths when we control this pest in the field, especially the weight of female G. molesta, which may be affected by nutrition and will affect population dynamics in the following generation.

Key words: Grapholitha molesta, pupal weight, fecundity, adult longevity, larval development