How many kinds of bugs are there? An estimate last year, according to the journal Science, based on mathematical modelling and a major bug-counting effort in New Guinea, puts the number of arthropod species in the tropics – which account for most of the animal species in the world – at about 3.7 million. And they feature such varied sex lives as to make Casanova look like a rank amateur.
Of course, had the great seducer been a mantis rather than a Venetian, things might have come to an early end. Female mantis are prone to make a meal of their suitors following – sometimes even during – their copulation, commencing on their mate’s head. There is method in their cannibalistic madness. The male head contains the nerves that control copulation. No head, no nerves, nothing to stop the abdomen keeping up the good work.
Females of the 900-odd species of seed beetles from the family Brucidae are not so lucky. The males sport ferociously barbed penises. There are no niceties about their sex life. The males attack the females, willing or no. Not only does the female seed beetle find it impossible to part from her attacker, she frequently suffers fatal injuries. This may be driving seed beetles extinction, according to recent research by an international research team headed by evolutionary biologist Daniel Rankin from the University of Zurich.
They demonstrated in a mathematical model that as the males become more and more aggressive, increasing numbers of females are harmed during mating and die from their injuries. In economics, such clashes between individual and group interests are referred to as the “tragedy of the commons.” “In nature, there are many examples of the tragedy of the commons,” says Rankin (Science Daily). Since these are a worldwide pest of stored grain and other seeds, it may not be so much of a tragedy, however.
Other major pests are aphids. Here the female gets off easy, mating but once a year. But she can happily procreate without indulging in the act by a process known as parthenogenesis. Unfortunately for a number of reasons, aphids require symbiotic bacteria to survive. The only way they can obtain a full complement of these is through conventional coupling – if only annually. And yes, we have heard that joke.
Insect genitalia provide some of the best clues as to their identities. But examining them once the insect is dead is often difficult, so Australian scientists devised the vesica everter, or ‘Phalloblaster.’ The device inflates the genitalia with a stream of pressurized alcohol to create the same shape as when the insect was alive.
Also thanks to the Australian Broadcasting Corporation, we now know that penises come in pairs in earwigs of the family Anisolabidae. In particular, males of the species Euborellia plebaga have two penises that are often larger than the earwig’s one-centimetre body.
Entomologists seem to have a strange fascinating with the male reproductive organ. In fact, notes the journal Science, when it came to insect penises, Charles Darwin had it right. The famed naturalist suspected that insect genitalia, which are frequently festooned with bizarre combinations of hooks, spines, and knobs, essentially function like peacock tails. That is, they helped males beat out their rivals for females. Now says Science, researchers have confirmed this hypothesis by zapping fly penises with a laser.
Scientists haven’t been left out over in Germany. An ancient daddy long legs, or harvestman, 400 million years old was discovered in Scotland by researchers from Humboldt University, Berlin, Germany – the oldest such genitalia yet known. The penis of the ancient insect is two-thirds the length of the insect’s body and very similar to modern day harvestmen.
Stick insects indulge in the same parthenogenesis in order to reproduce but apparently have no need for bacterial assistance. This, suggested Julia McKinnell writing in Maclean’s magazine, should make them good pets to have around small children who are likely to otherwise ask awkward questions.
Meanwhile, the male bed bug is not interested in the niceties of gentle sex. He rams his phallus through the unfortunate female’s body wall in an act entomologists refer to as “traumatic insemination.” Knowledge of this surely will only increase disgust at these unpleasant creatures. Or to discover that cockroaches urinate on each other to assist insemination and their couplings may last for days.
As if all this isn’t enough African bat bugs turn out to be transsexual. Male bat bugs sport female genitalia that mimic the male’s version of the female bits – as well as their own redundant vagina, explained Rowan Hooper in New Scientist. Research revealed that they had scarring on their abdomens similar to that of the females following copulation. In other words, males had been using their penises to stab other males.
Why would a female bug prefer a mate half her size? In the case of the Cook Strait giant weta, Deinacrida rugosa, a sort of badly stuffed cricket, the smaller males move faster in the race to reach home base. Having found her hiding hole, he spends a day there copulating repeatedly. For the record, the difference in sizes is called dimorphism and, according to Natural History magazine, is both common and “fascinates biologists.”
Widespread use of pesticides has reduced the chances of sighting the display fireflies indulge in to attract the opposite sex. There are various species of the insect, and in each the male emits a specific series of timed flashes to which the female responds with her own signals. Alas for the would-be lovers, the predatory female Photuris firefly is capable of imitating the female light signals of up to 11 other species, attracting love-smitten males to their doom in her eager jaws.
A human imitator uses some of Photuris’ wily ways to attract an audience. Supermodel and movie star Isabella Rossellini makes movies illustrating the sex life of bugs and other small critters. She achieves this by dressing up as her subjects and accurately imitating their intimate acts using paper cutouts. Dubbed Green Porno, they attracted the attention of the Sundance Channel, she explained to Scientific American’s Charles Q. Choi.
Ms Rossellini appears to have given a miss to the female bean weevil, Acathoscelides obtectus, who would rather drink her mate’s ejaculate than use it to fertilize the eggs, Michael Brooks explained in a recent issue of New Scientist. It turns out, he says, that reproduction is a complex affair. Human sexual exuberance, he concludes, is tame compared with some of the things animals get up to in the name of reproduction.
