3/30/09 6:05

Cohabiting and pre-'mature' copulation. It is not uncommon for some widows and other spiders to pair and mate while the female is still in the penultimate stage.

Cohabiting usually takes place after the sub adult female is sated, otherwise the adult male will likely be perceived as prey (although it may be the other way around with species where the adult males actively hunt) or an intruder, and greeted with hostility. The longest period of cohabitation I have witnessed with species that generally do not tolerate the presence of conspecifics (which is most spiders) was a week, week and a half maybe.

Generally mating takes place prior to the final molt, when the female is basically an adult just needing to get out of its sub adult skin. The earliest I have observed copulation with a sub adult female was about 48 hours (L. geometricus). The images here were minutes before the final molt. However, there has been a report of a wild caught sub adult female Phidippus that was not sated, not preparing to molt, and was reared to maturity in captivity without ever being introduced to a male, and it produced a fertile sac. This would suggest (to me at least) that after spiders molt they start developing into the following stage. Sub adult female spiders of different 'ages' (immediately after penultimate molt, a few weeks to a month after) should be investigated regarding reproductive organ development. Reproductive organs are obviously developed in some species prior to final molt, although other species cohabit but the male will not copulate until immediately after the female molts. I don't know what that indicates.