Over the course of the annual cycle, migratory bird populations can be impacted by environmental conditions in regions separated by thousands of kilometers. We examine how climatic conditions during discrete periods of the annual cycle influence the demography of a nearctic-neotropical migrant population of yellow warblers (Setophaga petechia), that breed in western Canada and overwinter in Mex...

In the United States, Ixodes scapularis ticks overwinter in the Northeast and Upper Midwest and transmit the agent of human granulocytic anaplasmosis, Anaplasma phagocytophilum, among other pathogens. We now show that the presence of A. phagocytophilum in I. scapularis ticks increases their ability to survive in the cold. We identified an I. scapularis antifreeze glycoprotein, designated IAFGP,...

Epidemiology of vectored plant pathogens involves the plant, the pathogens, the vectors, and the environment, all interacting in various ways. Often, an understanding is needed of seasonal cycles of host plants, pathogens, and vectors. For example, pathogens and vectors important to an annual crop may have non-crop reservoirs between harvest and re-planting. Vectors may overwinter in the crop, ...

In subarctic Newfoundland, age-0 Atlantic cod (Gadus morhua) settle into coastal habitats in several summer–autumn pulses, resulting broad length-frequency distributions before winter. Low winter temperatures and potential decreases food availability pose challenges for young-of-year fish. To examine how size variation affects overwintering success under contrasting scenarios, we conducted 114-...

In central Europe, the hybridogenetic water frog Rana esculenta is a sexual parasite that only persists in the presence of the parental species, R. lessonae, with which it must mate in order to reproduce. R. esculenta is a superior larval competitor, and adult females are about three times more fecund than R. lessonae. This suggests that, in the absence of some balancing advantage to R. lessona...

The sweetpotato whitefly Bemisia tabaci Q species is a recent invader and important pest of agricultural crops in China. This research tested the hypothesis that the Q populations that establish in agricultural fields in northern China each year are derived from multiple secondary introductions and/or local populations that overwinter in greenhouses (the pest cannot survive winters in the field...