Effect of age at first mating on primary sex-ratio of the two-spotted spider mite

This paper determines the influence of initial age at mating on the primary sex-ratio of the two-spotted spider mite Tetranychus urticae Koch. The specific question asked is whether females that mate at ages beyond ecdysis, or are inseminated at ecdysis by virgin males of set ages, have daughter productions different from control females mated at ecdysis by randomly aged males. Age of initial female mating did not affect survival. Females mated at ecdysis produced more daughters than those mated at age 5 or 10 days. However, daughter production was equal for all female treatments in the post-mating period. All treatments stopped producing daughters at approximately the same age, regardless of when mated. Son production was lowest for females mated at ecdysis. However, son production by females mated when 5 or 10 days old was lower than that of females mated at ecdysis.