Post-copulatory fitness- mating effects on female receptivity and productivity
To test whether sexual perception could lead to altered female remating behaviour (mediated by the differential transfer of accessory gland proteins; Hopkins et al. , 2019), we monogamously housed 135 females (71 treatment females and 64 control females) with a standard virgin male (4 days old) and monitored remating latency over a period of 8 hours. This was done on the day following the initial mating. We discarded successfully remated females (i.e. at least 10 minutes long copulation) and isolated females that had failed to mate. The next day, we presented these unmated females to another standard virgin male, in a new vial, for up 8 hours. We ran remating trials for 4 successive days (i.e. starting 24h, 48h, 72h and 96 hours after the end of the first mating), after which a large proportion of the females had remated (110 out of 135, over 4 days). Females that did not remate following these 4 days were discarded, but accounted for in the remating latency analyses (right-censored, see below). When calculating remating latency over many days, the time between two remating trials was not included; i.e. maximum remating latency over 4 days was therefore 8 hours * 4 remating trials = 32 hours (1920 minutes).
We also monitored daily reproductive output of 135 focal females (71 treatment females and 64 control females) over the 7 days following the initial mating, in order to assess whether sexual perception could lead altered female immediate reproductive output (mediated via accessory gland proteins transferred within the seminal fluid). Following the initial mating, we flipped females into new vials every day in order to obtain a daily measure of female early-life reproductive output. Past seven days, we flipped females into new vials every 3-4 days until natural death. We incubated vacant vials for 15 days to allow F1 offspring emergence (average generation time being ca. 10 days), after which we froze them at ca. -20°C for later counting. Given that females only mated once, female lifetime reproductive success could serve as an indicator of the number of sperm transferred by experimental males (female-exposed or control males).