Production of Sexuals in the Aphid Acyrthosiphon kondoi in Japan (Homoptera: Aphidinea: Aphididae)
This study is to determine the regional difference in the photoperiodic responses between 2 clones of the blue alfalfa aphid, Acyrthosiphon kondoi Shinji 1938. Experiments were carried out under 6 photoperiods ranging from: 16L: 8D at - 8L: 16D at 15°C. Mothers of the Kurashiki clone, originating from the S'part of Japan produced only virginoparae (Vgp) even in the shortest photophase, whereas mothers of the Sapporo clone, originating from the N' part of Japan produced Vgp, SX-♀♀ and -♂♂. Under long photophase (14 h) the Sapporo clone produced only Vgp, at slightly shorter photophases of 13.5 h and 13 h it produced Sx-♂♂ and Vgp, and at photophases of 12 h and 8 h, Sx-♀♀,-♂♂ and Vgp were all produced. In the latter case, Sx-♀♀ appeared first, then -♂♂, and finally Vgp.