Figure 1

Mean ± s.e.m. δ¹⁵N‰ values of spermathecae of inseminated (filled symbols) and uninseminated (open symbols) females from experiments 1–5. Male age at the start of the experiment is given. N is the number of spermathecae analysed for inseminated (+) and uninseminated (-) females. The dotted line indicates the threshold value of 3 s.d. above mean δ¹⁵N‰ of virgin females. Virgin (V) and Standard (St) samples are included. Dissection treatments are: I: females dissected immediately after mating; II: females isolated and dissected 3–5 days after mating (with the number of days used added in between brackets). Values with different letters are significantly different at p < 0.05 with comparisons made between dissection treatments I and II for each experiment. Asterisks indicate significant difference between spermathecae of inseminated and uninseminated females for each treatment at * p < 0.05, and ** p < 0.01 (comparisons made with independent t-tests or Mann-Whitney U tests).