Adult survival and reproduction in an arctic mite, Ameronothrus lineatus (Acari, Oribatida): effects of temperature and winter cold
Survival and reproduction of an arctic population of Ameronothrus lineatus were studied at four constant temperatures (5, 10, 15, and 21 °C). By simulating winters in the laboratory, an adult population was followed through 3 "years". Increasing temperatures reduced adult longevity. Females survived longer than males. A temperature of 15 °C was the most favourable for reproduction, with highest larviposition rate and reproductive output. Lifetime reproductive output was also high at 10 °C, while lower numbers of larvae at 21 °C indicated the beginning of heat stress. Comparison with field data showed that the reproductive performance at 15 °C corresponded to reproduction in a natural population experiencing a mean temperature of 89 °C, suggesting a positive effect of daily temperature fluctuations. A simulated winter with freezing temperatures increased male survival and positively affected all aspects of reproduction the following laboratory summer.