Variability in diapause propensity within populations of a temperate insect species: interactions between insecticide resistance genes and photoperiodism.

Boivin, Thomas; Bouvier, Jean-Charles; Beslay, Dominique; Sauphanor, Benoit

Temperate insects generally use day length as a reliable cue for long-term seasonal changes in their environment. Significant variation in photoperiodism between and within populations is thought to be associated with genetic variation resulting from local adaptation. In this study, we investigated whether genetic variation associated with selection for insecticide resistance may be a source of divergence in the photoperiodic timing of diapause through pleiotropic interactions. Critical photoperiods for diapause induction were estimated in one susceptible and two insecticide-resistant homozygous strains of the codling mothCydia pomonella, as well as in their reciprocal F1 progeny. Diapause responses to naturally decreasing day length were subsequently followed in the laboratory strains and in two field populations ofC. pomonellain south-eastern France. We found higher critical photoperiods for diapause induction in homozygous resistant individuals than in both homozygous susceptible and heterozygous ones. This partly explained the significantly earlier timings of diapause found in homozygous resistant individuals of both laboratory and field populations ofC. pomonellaunder natural photoperiods, relative to those found in both homozygous susceptible and heterozygous ones. We assume that adaptive genetic changes associated with selection for insecticide resistance may generate substantial variation in the seasonal timing of diapause, an essential ecological feature of the fitness of insecticide resistance genes in this species. © 2004 The Linnean Society of London,Biological Journal of the Linnean Society, 2004,83, 341–351.

PHOTOPERIODISM; PHYSIOLOGICAL effects of light; BIOLOGICAL rhythms; INSECTS; GENES; HEREDITY

Biological Journal of the Linnean Society, 2004, Vol 83, Issue 3, p341

0024-4066

Academic Journal

10.1111/j.1095-8312.2004.00392.x