Published online by Cambridge University Press: 31 May 2012
Betulaphis quadrituberculata (Kalt.) is an inconspicuous leaf-feeding aphid on birches in North America and Europe, now recorded on Betula papyrifera Marsh and B. alleghaniensis Britt. in the Province of New Brunswick. Some aspects of its morphology are described in order to complement the incomplete accounts already in the literature. The viviparae are seasonally polymorphic in size and color.
In New Brunswick the aphid has an annual monoecious holocycle comprising up to 10 generations. The seasonal history and habits of the various morphs are described. The insect disperses mainly by the flight activity of the stem-mothers in spring, but in succeeding generations almost all individuals are apterous and rather sedentary in habit. Data on rate of development and fecundity are presented and briefly discussed as factors contributing to the seasonal population pattern.