The complex sex lives of gold swift moths

Chuck Bednar for – Your Universe Online
The mating habits of the animal kingdom tend to be fairly basic and predictable, but one type of insect has tried to spice things up a bit by opting to use a variety of different mating patterns and sexual positions during its reproductive ritual.
The creature in question is the gold swift moth (Phymatopus hecta), and according to researchers from the University of Leeds’ School of Biology, it has one of the most complex sex lives in the insect world. In fact, research published last month in the Biological Journal of the Linnean Society suggests that its reproductive repertoire reads like an insect version of the Kama Sutra.
“With most insects, you expect to find a fairly set mating process. In moths like this, you might see the female staying still, emitting a scent and then mating with the first male moth to arrive,” explained study author Professor John Turner. “Colleagues have commented that this is the most elaborate mating procedure known in any insect and I have certainly not observed anything to surpass it.”
The gold swift moth usually performs its courtship rituals throughout wooden areas of the UK during June and July, and Professor Turner said that he and his colleagues have identified a plethora of different courtship “dances” used by the creatures. In fact, they report that the moths were able to pull out a fresh set of moves if their first attempts failed to produce the desired response.
They can use the classic moth mating pattern in which the female hangs from foliage and emits a scent, then mates with one of the males that arrives on the scene. Alternately, the male can be the one hanging from foliage, with the female traveling to him for mating, or they can perform a mutual ceremony when a female flies up to a hovering male and they “dance” in the air together.
In some instances, a group of males can form a hovering swarm and follow the females as they fly out of the swarm. Once the female lands by hanging under a leaf, a male lands next to her and they mate. Also, a male could hang from foliage, only to have a female land nearby and fan her scent towards him using her wings to get his attention so they can fly off together.
Similarly, a female can fly at a hanging male, bump into him and land nearby. The male then flies towards the female, hanging beside her and fluttering, before the two go off to mate together. Professor Turner also reported observing “fighting dances” between males and the occasional “homoerotic” courtships, in which males embarked on mating procedures with other males. He suggests the later is caused by confusion due to the nearby triggering of female scents.
“I intervened on some occasions to stop the mating,” he explained. “The insects would pause and then resume using a different pattern. It started to look a bit like a human courtship, with the moths doing it every which way and having a whole range of tactics for attracting a mate.”
The researchers also found that the moths tended to vary their sexual positions. Unlike most types of insects, they used two primary approaches: one in which the male hangs facing the female, reaches over to connect his abdomen to hers, and then lets go so that he hangs there freely until sunrise; and another in which he hangs with his back to her, bends his abdomen backwards, and then twists around with his mate until their bodies are connected.
Variations on both primary positions were also observed, and the study authors conclude that the complexity of their mating rituals are evolutionarily stable, likely having persisted in the species for tens of thousands of years. They believe that the relative scarcity of the moth’s mating grounds could explain the phenomenon, as both male and female members of the species have to live together in restricted areas that could encourage the development of new ways to find mates.