Genetic and phenotypic variation in juvenile development in relation to temperature and developmental pathway in a geometrid moth

Life histories show genetic population-level variation due to spatial variation in selection pressures. Phenotypic plasticity in life histories is also common, facilitating fine-tuning of the phenotype in relation to the prevailing selection regime. In multivoltine (≥ 2 generations / year) insects, individuals following alternative developmental pathways (diapause / direct development) experience different selection regimes. We studied the genetic and phenotypic components of juvenile development in Cabera exanthemata (Lepidoptera: Geometridae) in a factorial split-brood experiment. F2 offspring of individuals originating from populations in northern and central Finland were divided among manipulations defined by temperature (14ºC / 20ºC) and day length (24h / 15h). Short day length invariably induced diapause, whereas continuous light almost invariably induced direct development in both regions, although northern populations are strictly univoltine in the wild. Individuals from norther...生命史特征因选择压力的空间异质性而呈现种群水平的遗传变异。生命史的表型可塑性亦较为普遍，可根据当前的选择体系对表型进行精细调控。在多化性（multivoltine，一年≥2代）昆虫中，采取滞育（diapause）与直接发育（direct development）这两种不同发育路径的个体，所经历的选择压力体系存在差异。我们通过析因分群实验（factorial split-brood experiment），研究了白波纹尺蛾（Cabera exanthemata，鳞翅目Lepidoptera：尺蛾科Geometridae）幼体发育的遗传与表型组分。实验材料为源自芬兰北部与中部种群的亲本个体所产生的F2代子代，将其分配至由温度（14℃/20℃）和光周期（24h/15h）设置的各处理组中。尽管芬兰北部种群在野外严格为一化性（univoltine）类群，但在两个区域中，短光周期均会诱导滞育，而持续光照则几乎均会诱导直接发育；来自北部种群的个体……