Research Institute for Subtropics
Fruit Fly Research in Japan

 

Effects of Aging and Temperature on the Male's Reproductive Development of the West Indian Sweetpotato Weevil, Euscepes Postfasciatus (Fairmaire) (Coleoptera: Curculionidae)

<Author> Satoshi HIROYOSHI ; Seiichi MORIYA
<Year> 1999
<Journal> Entomological Science
<Volume> 2
<Issue> 2
<Pages> 165-171
<Notes> English

Effects of aging and temperature on the reproductive development of unmated male adults of the West Indian sweetpotato weevil Euscepes postfasciatus were studied. Under 14L-10D and 25 deg C, the testes slightly increased in size only during the first 10 days after emergence, whereas the numbers of sperm in the testes-seminal vesicles complex greatly increased with age, at least between day 5 and day 60 of their adult life. Short and long types of tubular accessory glands (TAGs) and their contents greatly increased with age until day 20 and then the rate of increase reduced. In order to assess the effect of temperature on reproduction, weevils were reared at 18, 22, 26 and 30 deg C for the examination of TAGs development, and at 15, 20, 25 and 30 deg C for the spermiogenesis. The lower the temperature, the more the development of TAGs and the rate of spermiogenesis were reduced. It is likely that the male's reproduction may be suppressed by low temperatures during winter.


Research Institute for Subtropics