Data from: pre-copulatory choices drive post-copulatory decisions: mechanisms of female control shift across different life stages

The 'wallflower' hypothesis proposes females mate indiscriminately to avoid reproductive delays. Post-copulatory mechanisms may then allow 'trading up', favouring paternity of future mates. We tested links between pre- and post-copulatory choice in Latrodectus geometricus female spiders paired sequentially with two males. These females copulate as adults or as subadults and store sperm in paired spermathecae. Choosy adults have a higher risk of delays to reproduction than subadults. We predicted low pre-copulatory, but high post-copulatory choice at first matings for adults and the opposite for subadults. At second matings, we expected all females would prefer males superior to their first. We found all females mated indiscriminately at their first pairing, but in contrast to subadults, adults usually copulated only once (leaving one spermatheca empty); a mechanism of post-copulatory choosiness. Adult-mated females were more likely to remate than subadult-mated (adult) females, showing a preference for larger males, while subadult-mated females tended to prefer males in better condition. Our results show that the 'wallflower' effect and 'trading up' tactics can be linked, allowing females to employ choice even if rejecting males is costly.

Data were collected in a laboratory experiment in which brown widow females each mated with two males:

• First, subadult and adult females mated with naive males.
• Next, adult females who had previously mated either as a subadult or adult related with new naive males.

Mating trials were video recorded and the occurrence and timing of courtship and mating behaviours were scored by an observer. See the paper for full details of data collection and analysis.