Clonal variation of sexual morph production in response to temperature and photoperiod in soybean aphid, <Emphasis Type="Italic">Aphis glycines</Emphasis> (Hemiptera: Aphididae)

The life cycle of Aphis glycines Matsumura (Hemiptera: Aphididae) has been recognized as holocyclic. This study examined photoperiod and temperature effects on fecundity and sexual morph production using six A. glycines clones collected in northern, eastern, western, and southern Japan. Results showed that the six clones included anholocyclic and intermediate ones. Low temperature and short photoperiod negatively affected fecundity, except for one clone with anholocyclic life cycle. Possible mechanisms for the year-round parthenogenetic production of the anholocyclic clone are discussed.