Effect of pupal exposure to different photoperiods on emergence, mating and reproduction of Grapholita molesta (Lepidoptera, Tortricidae

Author of the article:WANG Yi1** KONG Wei-Na2 GUO Yong-Fu1 CHAI Xiao-Han1 LI Jie3 MA Rui-Yan1***

Author's Workplace：1. College of Agriculture, Shanxi Agricultural University, Taigu 030801, China; 2. Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Institute of Plant Protection, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, China; 3. Gardening Research Institute, Shanxi Academy of Agricultural Science, Taigu 030031, China

Key Words：Grapholita molesta; photoperiods; pupae

Abstract： 

[Objectives]  To investigate the effect of pupal exposure to different photoperiods on the emergence, mating and reproduction of Grapholita molesta (Busck), a globally important fruit-boring pest. [Methods]  Previous laboratory studies show that the behavioral rhythm of emergence and mating in this species vary with duration of light exposure. Pupae were exposed to 10 different photoperiods (L︰D = 0︰24, 2︰22, 4︰20, 8︰16, 12︰12, 15︰9, 16︰8, 20︰4, 22︰2, 24︰0) and the pupal period, mating age, mating duration, mating rate, the number of fertile eggs and adult longevity, were recorded and compared among treatments. [Results]  The pupal period of the 8L︰16D treatment group was the shortest. The mating rate and number of fertile eggs of the 0L︰24D treatment group were the lowest, and the mating age of the 24L︰0D treatment group was the highest. Female and male longevity were highest at 12L︰12D or 2L︰22D. [Conclusion]  Exposing pupae to different photoperiods significantly affected emergence, mating rate and fecundity. Because photoperiod is closely related to latitude, this sensitivity to photoperiod could cause differences in generation number, generation time and abundance over the species’ range. In nature, both temperature and photoperiod can directly affect the occurrence of G. molesta, a species that also has the capacity to has anticipate photoperiod.