How many times has this happened to you: You put a male and a female mantis together for them to mate, leave for a few hours, and after a while see that the male has been eaten and you panic because you don't know if the female mated or not? Well here's the answer (inspired by when katnapper told me there was no way to tell if her creobroter nebulosa mated before the male was eaten, remember that topic?). After mating, the end of the female's abdomen will be open for a while, which is how you can tell if they mated. I have observed this in chinese mantids, the abdomens are open for a day or two after the intercourse. And there you have it. Also, if the female didn't mate, a week later a male will usually want to mate with her, because once a chinese female of mine ate the poor male, and 5 days later she mated with a different male.
