Effects of quality of resource and fertilization status on some fitness traits in the two-spotted spider mite, Tetranychus urticae Koch.

Four fitness traits, including fecundity, hatchability, duration of oviposition, and longevity, were studied in T. urticae. Comparisons were made between unfertilized and fertilized females reared on good and poor resources. Significant differences in total egg production, duration of oviposition, and longevity were observed with respect to fertilization status. Only total egg production varied significantly between maternal background environments. Hatchability was uniformly high. Fecundity was found to be the most influential character affecting fitness in spider mites. Further analysis of the distribution of daily egg productions was used to determine the various factors affecting intrinsic rates of increase including the rate of development, time of peak egg production, and duration of oviposition. The rate of development was shown to be the most important factor determining the intrinsic rate of increase. The relationships between these findings and the colonizing ability of spider mite populations were discussed.