For animals like the praying mantis, green anaconda and certain species of octopus, the female of the species is certainly more deadly for the male, and it’s the male that pays the ultimate price for passion, says Aoife Glass.
.What’s arguably worse - for the male at any rate - is that many of these animals don’t just kill their mates; they practice something called ‘sexual cannibalism’ and yes, that’s exactly what it sounds like.
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The female will eat the male after, and in some cases even during, mating. Think of it as dinner and a date all at the same time.
While some of these animals are probably familiar, there are a few that will be a surprise! And not every male is destined for death - some have ingenious and devious ways of avoiding their fate.
9 deadly, brutal females that lure males to their death
Praying Mantis
The praying mantis is probably the most famous species to commit mariticide. When a female mantis and a male mantis get together, the male can quite literally end up losing its head!
Due to the position the male adopts in front of the female during mating, with that juicy head just in front of her sharp mandibles, it’s no wonder she can’t resist a little decapitating love bite, and it doesn’t interrupt coitus - the headless male will simply continue to mate until finished.
However, contrary to popular belief, the male’s death is not inevitable. In some species, like Tenodera sinensis it only happens 28% of the time, while in others like the springbok mantis (Miomantis caffra) it can be up to a whopping 60% - though the males do sometimes fight back to avoid becoming lunch.
Blue-lined octopus
Like many cephalopods, sexual cannibalism is common among octopus like Hapalochlaena fasciata (blue-lined octopus). The females of this species are much larger than the male, up to twice the size of their potential partners. It also takes a lot of energy for the female to lay and look after the eggs, so a pre-egg laying meal is a good survival strategy for the species. But not all males are happy with their lot.
Like all octopus, this species are venomous, using the potent neurotoxin tetrodotoxin to hunt and for protection. This neurotoxin is even powerful enough to kill humans, so it was a surprise to researchers when it was discovered it is sometimes used during octopus sex. Males were observed injecting females prior to copulation with a dose that renders them paralysed for around one hour; long enough to transfer sperm to the female and make a safe getaway.
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Australian red back spider
The black widow spider is synonymous with lethal femme fatales, but their reputation might be a little unfair. While sexual cannibalism in spider species is widespread and common, the true black widow spider species of North America don’t tend to display this behaviour in the wild - observations in captivity, where stress can alter natural behaviour, are where this view originated.
However, having your mate for dinner - literally - is common in the wider Latrodectus genus which also includes Australian red back spiders (One of the deadliest spiders in the world). The bigger female will frequently consume her mate, and some males even commit what’s known as copulatory suicide, literally throwing themselves into the jaws of their partner.
There is a species-survival benefit to this; females who consume males will often reject a subsequent partnering, meaning that the male's sacrifice makes his genetic material more likely to be passed on to subsequent generations.
Green anaconda
Picture a writhing mass of snakes, submerged in water, as multiple males wrestle to mate with a large female over the period of several days. That’s what sex is like for the green anaconda (Eunectes murinus), and it carries one major risk as the larger females have been known to munch on a male once the mating is done.
While it might be cold comfort to the deceased male, there’s a good reason why females might appreciate a post-coital meal. It’s estimated that females can lose between 30 - 50% of their bodyweight producing offspring, partly because anacondas give birth to live young, after gestating their young for six to seven months. A good feed certainly would certainly help the female keep her energy up during this period.
Scorpions
While some males sacrifice their lives for the good of species survival, like the praying mantis and Australian red back spider, for other animals it can just come down to a case of the munchies. That’s the case with scorpions.
It used to be thought that various scorpion species practiced sexual canniballism, but further study indicates that the behaviour might be more closely related to how hungry the female is.
If the female is undernourished, she is more likely to eat the male, and otherwise this behaviour isn’t really observed. This type of ‘economic’ canniballism is seen in a number of different animals, and is likely also true of the cannibalism practiced by the green anaconda.
Jumping spiders
Male jumping spiders have got the moves - and they need them! As the name suggests these acrobatic arachnids are known for their spatial awareness, and they use this to good effect when it comes to mating. Their lives might literally depend on their dance skills.
Sexual dimorphism is prevalent in jumping spiders, so when a male approaches a female it needs to let her know his intentions are amourous, and that he’s not lunch. He does this by conducting an elaborate dance. However, if the dance isn’t impressive enough, or if the female just isn’t in the mood, he might end up as food anyway.
Even if he does manage to copulate with the female, he’s not necessarily safe as she might still go for the kill. To avoid this, some male jumping spiders have another trick; they can use their gymnastic skill to catapult themselves away from female to a safe distance.
Photorus firefly
The Photorus firefly is a genus of beetle, and the females of this genus are the sirens of the insect world. While the seductive mythological monsters used a hypnotic and alluring song to entice and kill hapless sailors, this beetle uses its bioluminescent light source to find food.
Each species of firefly has its own particular sequence of light flashes that its females use to attract a mate. Female Photorus weaponises this for its own end, mimicking the light patterns of other species. When a hopeful male appears, rather than finding a mate it finds a hungry Photorus which will then proceed to kill and consume it.
Angler fish
Imagine losing yourself in a relationship so completely that you forsake independence and your own identity. For male anglerfish, that’s a sacrifice worth making.
In the vast black depths of the oceans, finding anything at all is tricky, so it's understandable that once you’ve managed to find a partner to mate with, you’ll hang on to them for all your worth.
When a male anglerfish finds a female to mate with, he fuses his body to hers - his tissues dissolve, their circulatory systems fuse, and he becomes a kind of portable sperm production appendage. This kind of sexual parasitism means that whenever she is ready to reproduce, she has all the materials she needs on hand.
Antechinus
Antechinus are a type of small marsupial endemic to Australia. They are cute, furry, small… and the drive to reproduce with a female is so strong that the males will literally mate themselves to death en masse.
This species has a short breeding window, an adaptation to environmental factors. When mating season kicks off, it can last up to 12 hours with males actively seeking mates night and day thanks to an increase in corticosteroids in the blood. This allows them to use up every gram of stored energy in their body for this purpose, and males will mate with several females before keeling over dead.
