Insects aren't gay, they're just enthusiastic! Scientists discover same-sex mating in bugs is down to a rush to reproduce
- In the rush to reproduce, insects don't have time to check the sex of a mate
- Male insects that have recently mated with a female may smell feminine
- Researchers claim this can lead to the mating bug becoming confused
- They add homosexual mating is as least as dangerous as heterosexual mating, yet without the benefit of reproduction
Despite the vast majority of male insects regularly taking part in homosexual activities, such as courting and mating, scientists claim it isn't because they are gay - instead they may just be confused during the throes of reproduction.
In the rush to reproduce, researchers from Tel Aviv University claim insects don't have time to check the sex of a mate so are homosexual 'by accident'.
The study found there are no clear benefits for certain species of insects to have same-sex relationships and concluded they may be duped into thinking another is a female, either because of how similar they look or by scents they have picked up.
Flour beetles, pictured, are one insect species in which males choose to mate with each other. Scientists from Tel Aviv University claim it isn't because they're gay, instead they may be confused. In the rush to reproduce, researchers claim insects don't have time to check the sex of a mate so are homosexual 'by accident'
HOW SAME-SEX MATING CAN LEAD TO PROCREATION
Gay sex in beetles was recently discovered to potentially increase a male's chance to indirectly fertilise females.
Sara Lewis from the University of Boston found male beetles will often mount each another, and in some cases transfer sperm.
Some of the sperm transferred could be 'accidentally' passed on when the recipient male later mates with a female.
Dr Inon Scharf of Tel Aviv University's
Department of Zoology and Dr Oliver Martin of ETH Zurich claim mating takes time and energy and can be dangerous, which makes homosexual mating even less appealing from an evolutionary perspective because it lacks the payoff of procreation.
'Insects and spiders mate quick and dirty,' claimed Dr Scharf. 'The cost of taking the time to identify the gender of mates or the cost of hesitation appears to be greater than the cost of making some mistakes.'
Yet despite the risks, in some species up to 85 per cent of males take part in homosexual behaviour.
researchers say this is not because bugs directly benefit from the
behaviour, but because they mistake other males for females. In
almost 80 per cent of homosexual cases, the researchers appeared to be
the result of 'misidentification or belated identification of gender.'
In some cases, males carry around the scents of females they have just mated with, sending confusing signals to other males. In others, males and females look so similar to one another that males can't tell if potential mates are female until after they have mounted them.
researchers claim insects and spiders have not evolved to be more
discriminating in their mating choices because the cost of rejecting an
opportunity to mate with a female is greater than that of mistakenly
mating with a male.
This explanation is supported by the fact many species that exhibit homosexual behaviour also mate with related species or inanimate objects, like beer bottles - indicating a general tendency toward misidentification.
In birds and mammals, homosexual behaviour has been shown to have evolutionary benefits; It provides 'practice' for young adults and maintains alliances within groups.
The male migrant hawker dragonfly. Up to 85% of males in certain insect species, including dragonflies, exhibit homosexual behaviour. The study claims this may because males carry around the scents of females they have just mated with, sending confusing signals to other males. In other cases, males and females look similar
Scientists recently tried to find explanations for similar behaviour in insects, suggesting it could serve to prepare for heterosexual courtship, dispose of old sperm, discourage predators, and distract competitors.
However, by reviewing research on 110 species of male insects and spiders, the researchers found the available evidence weakly supported such adaptive theories.
It is also possible sexual enthusiasm in bugs is related to other evolutionarily beneficial traits, the researchers say.
'Homosexual behaviour may be genomically linked to being more active, a better forager, or a better competitor,' said Dr Scharf. 'So even though misidentifying mates isn't a desirable trait, it's part of a package of traits that leaves the insect better adapted overall.'
To confirm their theory, the researchers plan to study the conditions that make homosexual behaviour more or less likely in bugs. They also want to look more deeply into male resistance to homosexual mating.
The study was published in Behavioral Ecology and Sociobiology.