Some Experiments on the Influence of Environment Upon the Forms of Aphis Chloris Koch. (Aphididae)

Transgenerational seasonal timer for suppression of sexual morph production in the pea aphid, Acyrthosiphon pisum

“…Such strong suppression of sexual morph production has also been shown in other aphids, e.g., A. forbesi in southern North America, Aphis chloris and M. viciae collected from England, and Myzus persicae in Greece (Lees, 1960;Marcovitch, 1924;Margaritopoulos et al, 2002;Wilson, 1938). Lees (1960) suggested that a seasonal timer for sexual morph production is adaptive to avoid producing sexual morphs under short days in early spring.…”

“…Similar phenomena have been reported in other aphid species. In many previous studies, however, it was unclear whether the number of days or the number of generations from hatching is important (Campbell and Tregidga, 2006;Dixon, 1972Dixon, , 1971Dixon and Glen, 1971;Lushai et al, 1996;Margaritopoulos et al, 2002;Wilson, 1938). Temperature affects the duration for which the seasonal timer can function in M. viciae, whereas photoperiod has no effect on the duration in Aphis rubicola (Brodel & Schaefers 1979;Lees 1960).…”

Multigenerational maternal inhibition of prepupal diapause in two Trichogramma species (Hymenoptera: Trichogrammatidae)

“…Values indicated by different letters are significantly different (P < 0.05 by the Tukey HSD test of arcsine-square root transformed data). Wilson, 1938). In Trichogramma species, at least under the circumstances of the present study, the diapause-averting maternal effect was also practically absolute.…”

“…The similar results were obtained in experiments with Aphis chloris Koch. Aphis rubicola Oestlund, Drepanosiphum platanoides (Schrank), Eucallipterus tiliae L., Myzus persicae (Sulzer), and Phorodon humuli (Schrank) although in these aphids, the ability to produce sexuales gradually increased over several generations (Brodel and Schaefers, 1979;Campbell and Tregidga, 2006;Dixon, 1971Dixon, , 1972Margaritopoulos et al, 2002;Wilson, 1938). It is interesting that we have found both gradual (in T. principium) and relatively rapid (in T. telengai) waning of the maternal restraining effect.…”

“…It is known that in several insect species the incidence of diapause among the progeny of females that had undergone diapause was relatively low or even zero despite the strong diapause-inducing conditions (Campbell and Tregidga, 2006;Dixon, 1971Dixon, , 1972Henrich and Denlinger, 1982;Jackson, 1963;Lees, 1960Lees, , 1966Lushai et al, 1996;Saunders et al, 2002;Saunders, 2010;Simmonds, 1947;Wilson, 1938). In some of the cited studies the stability of this effect was estimated.…”