The effect of photoperiodic conditions and maternal age on the progeny sequence of the pea aphid Acyrthosiphon pisum Harris (Homoptera, Aphididae) from the Volga area.

摘要

Photoperiodic response of the pea aphid Acyrthosiphon pisum Harris from the Volga Area of Russia was investigated. The viviparous reproductive sequences are described for 19 photoperiods (0-24 h) at 20oC. The existence of two photoperiodic responsesis discussed: inducing sex determination, and inducing female morph determination. Both are threshold responses of the long-day type. Very short-day photoperiods are perceived by aphids as long-day ones. Male production is induced by about one hour shorter scotophases than oviparae production. The percentage of different morphs in the progeny is revealed to be not only under photoperiodic control, but also age-dependent. The progeny of young viviparae consists only of females. Male production begins 4-5 days later than that of females. Viviparae tend to form initial and terminal sequences in the progeny pattern in spite of short-day conditions. A comparison of photoperiodic responses of the previously studied clones of A. pisum with the clone in question is carried out.