The first thing a male dragonfly wants to do when he sees an intruder is to mate. If that doesn’t work, he will try to eat it, and as a last resort, he will fight to retain supremacy of his territory.
Some insects have really strange habits, others can teach us a few things about behaving well and, while many may take the instruction ‘go forth and multiply’ a bit too literally, a lot of animals depend on large numbers of insects to keep their bellies full.
Dragonflies and their cousins, the damselflies, perform an intricate mating ritual called the wheel. In this position, the male holds the female firmly by the head, while she bends her abdomen up and under to a sperm deposit on his thorax.
Termites are known for a sophisticated family organisation based on monogamy. Despite living in colonies of millions of individuals, breeding termites mate for life. Some species have only one king and queen in a colony, while others have several leaders (still the pairs mate for life and don’t conduct brief flings). This has made termites one of the most successful insects. Altogether, the 2 600 termite species account for about 10 per cent of the planet’s total biomass. (Their high-fibre diet means they also produce 11 per cent of global methane emissions, second only to ruminants such as cows and sheep.) Even more interesting is that in some termite species the divorce rate runs at about 50 per cent. Sometimes males walk out and often females invite new males in … with violent results.
In the ant world, a keen sense of smell is vital because all interactions are ruled by chemicals. In some species, it can be quite direct: the queen will climb to a high point when she is ready to mate, then stick her backside in the air and release a love pheromone that inflames the ardour of all males within range. Mating takes place in midair, on the ground or in a mating ball, where a queen is completely surrounded by a swarm of adoring males.
If that’s not enough drama, here’s how bees do it. As soon as a new queen arises (after murdering her sisters), she takes a nuptial flight in which she mates in midair with up to 15 drones. The drones die after their penises audibly explode, leaving the end inside her as a plug, and the queen returns with enough sperm to stock the entire colony by herself. She can lay up to 1 500 eggs a day during her three-year lifetime. Hard work, made easier by attending worker bees.
Beetles are in a class of their own. Flour beetles (Tribolium casteneum) are really promiscuous, even by insect standards. When they aren’t eating, they’re copulating. Males start by using a spiny penis to sweep out previous mates’ sperm before unleashing his own. The rivals’ sperm clings to a sweeping male, so females stand a one in eight chance of being fertilised by a beetle they’ve never met.
Fleas have many amazing features. They can suck their way through 15 times their own body weight of blood a day and their legendary jumping skills aren’t dependent on muscle strength. But the real masterpiece of flea engineering is its penis. Proportionally the longest of any insect, it has so many hooks, springs and spines that it can be compared to a Swiss army knife. It takes quite a long time to unfold and copulation can last up to three hours (that’s the equivalent of about six weeks for a human). Adult fleas are ready for this marathon as soon as they emerge. No wonder a single pair of fleas can produce another 50 000 in a month.
Mayhem for mating moths
Spare a thought for those poor moths whirling around lights. Male moths are attracted to light simply because they think it’s the moon. For more than 150 million years these visually impaired creatures relied on the giant orb to help them navigate in a straight line, keeping the moon’s rays at a constant angle during their nightly mating excursions, flying more or less on a steady course until they caught the scent of a female. Moth history took an unfortunate twist when the incandescent lamp arrived on the scene. Flying so close to these surrogate moons makes it nearly impossible for a moth to maintain a straight course, so it must constantly correct itself. Soon it becomes completely confused and, before you know it, the poor guy is fluttering around in circles. In the end the only solution is to resign itself to a celibate night on a strange porch.
Sources:
- The QI Book of Animals by John Lloyd and John Mitchinson, Faber and Faber (2009).
- African Insect Life, SH Skaife, Struik (1997).
- Hidden Wonders, Dan Lieberman and Rael Loon, Jacana (2008)
Photograph by Rachel Robinson
