Genetic Coordination of Diapause in the Pitcherplant Mosquito, Wyeomyia smithii (Diptera: Culicidae)

Six populations of Wyeomyia smithii from 30—49°N latitude maintain significant heritability for and consistently positive genetic correlations among three components of photoperiodically mediated larval diapause: (1) critical photoperiod, (2) required day number, and (3) depth of diapause. These traits then form genetically coordinated syndrome of traits that reinforce each other in a continuum from diapause-prone to diapause-resistant genotypes. We propose that this syndrome maintains genetic flexibility in a habitat that imposes fluctuating stabilizing selection on diapause.