By: Jennifer Welsh, LiveScience Staff Writer
Published: 05/08/2012 07:07 PM EDT on LiveScience

Violent sex is taken to an extreme in warehouse pirate bugs, where the male uses his daggerlike penis to break though the female's body wall and insert sperm directly into her abdomen. Now researchers have found that after enduring bouts of traumatic insemination, the females live fast and die young.

Those female warehouse pirate bugs take advantage of what life they have left and produce more eggs quicker than other pirate bugs.

"These multiply mated females died at a significantly younger age, but they started laying eggs earlier and at a higher rate to compensate," study researcher Thomas Cameron, of Umeå University in Sweden, told LiveScience in an email. "I would say it's not quite right to say that multiple mating is good for females, but it is something that they have evolved to deal with."

Though the warehouse pirate bug may be able to mate normally (inserting the penis into the female's reproductive tract), they seem to have ditched this for the traumatic type of mating, Cameron said.

warehouse pirate bugA male warehouse pirate bug with his genitalia extruded — you can see the daggerlike penis at the bottom of his abdomen.

That's a seemingly odd choice, since dagger-penis mating is dangerous: Traumatic insemination leaves gaping, seeping wounds on the female. The researchers wondered if this dangerous mating habit affected the female's life span or reproductive ability.

So they tested three groups of 21 female warehouse pirate bugs in the lab. The first group spent the day with a dead male bug, and stayed virgins. The second group mated with one male, and the third group mated with three males.

The females then lived their lives out in the lab under the researchers' watchful eyes. All of the mated females had a similar number of offspring, but the females that mated with the three males laid their eggs quicker and died earlier. [The Weirdest Animal Penises]

female wound An image of what the researchers believe is a mating wound on the female, with fluid seeping out.

The researchers think multiple matings may signal the females to lay more eggs every day, or the females could be injured from the dagger penises and worried about dying, so they laid more eggs earlier. The singly mated females could have also been waiting for more suitors to take a stab before laying their eggs.

Though their sex acts may seem scary, the warehouse pirate bug is important in keeping grain pests under control.

"It is quite a cool little beastie," Cameron said. "It is very adept at preying on immobile insect eggs, but when it gets the chance it pierces a moth or beetle larvae with this venom as then the prey crawls off and dies. The venom starts digesting the structure of the prey's body and the bug seeks it out and has a drink."

The study will be published tomorrow (May 9) in the journal Biology Letters.

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Check out this slideshow of other weird animal mating rituals:

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  • Angler Fish

    It's almost impossible to catch a male angler fish. Why? They don't exist for very long. When a male angler fish is born, it is a tiny creature with no digestive system. As such, it must swim to find a female angler fish as soon as possible. When it does, it bites and releases an enzyme that removes a part of her flesh allowing the male to fuse. Soon it becomes nothing but a small bump on the side of its partner. This lump stores the sperm needed for fertilization when the female is ready to reproduce. <a href="" target="_hplink"></a>

  • Garter Snake

    When a female garter snake is ready to mate, it releases a strong sex pheromone that drives hundreds of male gartner snakes to her location. Once there, the snakes form an intertwined pile of slithering bodies, covering the female and attempting to mate with her at the same time. This not only provides the female with a vast plethora of potential suitors, but also warmth and protection during the process.

  • Hippopotamus

    Hippos might look lackadaisical, but don't be fooled. They're among the most dangerous animals in the world, and are highly territorial. During mating, the male will empty his bladder and bowels in the surrounding water and use his powerful tail to splash the fecal water at a female of interest. Skip to 1:35. <a href="" target="_hplink"></a>

  • Camel

    Male camels who are sexually aroused attract females through excessive salivation, covering their mouths in a drooling white froth. But that's not all: they also expel a pink sack from the roof of their mouths called the doula, which hangs out from the side of their mouths to attract females. Skip to 1:13 to see the mating ritual.

  • Manakin

    The manakin is a small bird with a startling, stage-worthy mating ritual; the Moonwalk.

  • White Fronted Parrot

    As a part of their mating ritual, the white fronted parrot kisses its partner much like two humans might - except without the beaks. But unlike the standard french kiss, the male parrot adds a secret ingredient: vomit. <a href="" target="_hplink"></a>

  • Bean Weevil

    The bean weevil's penis is covered in sharp spines. Its genitals severely damage the inside of the female's reproductive tract, a phenomenon known as "traumatic insemination." <a href="" target="_hplink"></a>

  • The Porcupine

    During courtship, porcupine males stand on their hind legs and spray their partners with urine. If a female is ready to mate she will then allow the male to mount. <a href="" target="_hplink"></a>

  • Honey Bee

    After ejaculation, the male honey bee's genitals break away from the body and lodge themselves inside the queen bee's reproductive tract. This acts as a plug that blocks any other worker bees from mating with the queen. This insurance, however, comes at a cost, as the male honey bee dies soon after. <a href="" target="_hplink"></a>

  • Praying Mantis

    The praying mantis is infamous for its mating ritual. During coitus a hungry or stressed female will bite off the head of its mate and use it for nourishment. Unlike common belief however, this form of "rough" mating only occurs less than a third of the time. Nevertheless, the male mantis takes a definite risk in each attempt at procreation. <a href="" target="_hplink"></a>

  • The Giraffe

    To check if a female giraffe is ready to mate, the male will nudge her behind with his head to induce urination. He will then taste the urine to see if she is in heat. If so, he will follow her around until she allows him to mount. Interestingly, females that find a male to be particularly attractive have been observed to urinate more. <a href="" target="_hplink"></a>

  • Argonaut

    Male argonauts have a specialized tentacle, known as a hectocotylus, that holds a ball of spermatozoa on the end. In the vicinity of a female, this tentacle actually detaches from its host and swims towards the prospective mate. <a href="" target="_hplink"></a>

  • Echidna

    The porcupine-like echindna has a four-headed penis. Even more surprising is the coordination between the heads; they work in pairs, with only one pair active at any one time. The other pair rests, in preparation for the next round of mating. <a href="" target="_hplink"></a>

  • Banana Slugs

    Banana slugs have extremely long penises, some as long as their own body length. As hermaphrodites, two slugs will form the arrangement shown above in order to try to fertilize one another. In some cases however, a penis can get stuck in the middle of the attachment, holding two slugs together. The solution? The other slug chews it off.

  • The Frigate Bird

    A male frigate bird inflates a large throat sack, a mating ritual that takes a lot of effort and some time. Once it inflates, the sack looks like a big pink heart. To complete the ritual the male will shake its wings and sing a mating call.

  • Hyena

    Female hyenas are at the top of the hyena hierarchy. They are the more aggressive and dominate sex. This is because young female hyenas produce androgens, a similar hormone to testosterone, which increases aggression and competitiveness. It also enlarges the genitalia, creating a seven inch clitoris, or pseudo-penis. This gets tricky when a male tries to mate, and means that rape is extremely difficult. What's more, females have to give birth through their enlarged clitoris, which can cause serious complications for the mother. Skip to 1:23 in the video to get a better look. <a href="" target="_hplink"></a>

  • Brown Antechinus

    The brown antechinus is renowned for its hyperactive sexuality. Male antechinuses have been known to engage in coitus for hours with a single partner, only to move onto another. Eventually the male dies, a sexual martyr, from a lack of food and rest.

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