Summary 1.It has recently been demonstrated that the species of host plant used by males during larval development may significantly affect the reproductive success of both sexes in a polygophagous tortricid, Choristoneura rosaceana (Delisle & Bouchard 1995). In the present study, using the Spruce Budworm, C. fumiferana, the hypothesis was tested that in oligophagous species, similar effects would result from within-species variability in foliage quality. 2. It was demonstrated that male larval diet (young and old Balsam Fir foliage (YF vs OF) or artificial diet (AD)) significantly influences the reproductive success of both sexes of C. fumiferana. 3. Male body size and spermatophore size were positively correlated, with AD > YF > OF; however, males fed on YF had better mating success than those on OF and AD, indicating that size may not always be a good estimate of male quality. 4. The propensity of females to resume calling (CA + ) and remate (RM + ) was significantly lower, and the length of the refractory period longer, following first mating with high (YF) rather than low (OF and AD) male quality. 5. Females that resumed calling (CA + ) had a lower reproductive output than those that did not (CA -), with the effect being more pronounced following mating with males fed on low (OF and AD) rather than high (YF) quality diet. A similar trend was observed in the proportion of females that were unsuccessfully mated, as shown by their low incidence of fertility (<25%). In contrast to their reproductive output, females that resumed calling lived as long as those that did not, regardless of male larval diet. However, the resumption of calling was also observed in a large number of highly fertile (48%) females, indicating that infertility was not the only reason for the resumption of sexual receptivity. 6. Females that remated (RM + ) following an initial mating with low quality males (OF and AD) had fecundities and longevities similar to those that did not (RM -). However, their incidence of fertility was significantly higher. In contrast, females that remated following an initial mating with high quality males (YF) were more fecund and lived slightly longer than those that did not (RM -). A similar pattern was observed with females initially mated with OF and AD males, if only individuals with high fertility following first mating were considered in the analyses. 7. Male larval diet had no effect on fecundity, percentage fertility and longevity in females that remained refractory following their first mating. 8. The first mating occurred earlier in the night and lasted longer than the second, with both variables being independent of the diet of the first mate. This may explain why overall the proportion of females that remated was lower than that for females that resumed calling following mating.

No abstract

No abstract