When the early 19th-century scientist Thomas Malthus contemplated ways of reducing the population before it outstripped the food supply, he considered infanticide, murder, contraception, starving the poor -- and homosexuality. The latter has been harnessed by present-day scientists to halt an explosion, not of people, but of brown-tailed moths.

Moths and their larvae have multiplied in such numbers in some parts of the country recently that they have become a menace to people. Experts have come up with the novel solution of tricking the males of the species into thinking that they are gay.

Scientists are using a powder that spreads female pheromones -- the smell of sexual attraction -- and confuses the male moths, thus slowing the breeding. The powder is left near breeding grounds and, when larvae hatch, they are coated in it. Other male moths are then tempted naturally to make contact with them, believing them to be female. Moths have small brains and dreadful eyesight.