Surviving Sex: Black Widow Males Can Smell Potentially Cannibalistic Mates Coming

It's no secret that for spiders and many other predator bugs, reproduction can quite literally involve courting death. The black widow, infamous as its own widow-maker, is one of the most iconic cannibal spiders around. Now, a new study has revealed that male black widows have a fighting chance. They can smell if a female is hungry, helping them decide if courting her is worth the risk.

That's at least according to a study recently published in the journal Animal Behavior, which details how despite the infamy of their mating habits, black widow females only eat their mates two percent of the time. Researchers now suspect that this has a lot to do with male caution, where weary spiders only choose well-fed females who are less likely to make them an after-sex snack, if not earlier.

To reach this conclusion, a pair of researchers from the Integrative Behaviour & Neuroscience Group at the University of Toronto Scarborough, Canada exposed males to the sex signals (pheromones) of female spiders that were at various stages of hunger. Some of the females were satiated while others had been deprived of food for up to four weeks - resulting in reduced body mass and a marked drop in silk production.

The male black widows exposed to these pheromones showed far less interest in the signals of hungry females, compared to well-fed ones. If the females were ravenous, the males avoided them altogether.

Interestingly, the researchers suspect this only occurs because the males want to avoid being eaten specifically before they mate. In Australian redback spiders - a species that does not eat males during courtship no matter how hungry they are - they found that males will even court ravenous females. That's despite the fact that they will likely be doomed right after mating is done.

Evidently, spreading one's seed is enough for these redbacks, who are perfectly content in risking being eaten as long as they can sire little cannibals of their own.

What's more bizarre is that not all species work this same way. Researchers have previously determined that male mantids are actually more drawn to undernourished females, unwittingly offering their bodies as sustenance to ensure that the children they sire develop properly.

Other research has determined that many male spiders will voluntarily chew off their own genitals after sex to create a physical plug in the female. This stops any other males from mating with her even if she happens to eat her 'husband.'

Bugs, it seems, live up to their name as 'creepy crawlers' even in the bedroom.

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