Desirable daisies deceive male flies with sex offer

LONDON - Scientists have found that a South African daisy offers promises of sex to deceive male insects into spreading more of its pollen.

Many flowers produce nectar to entice pollinating insects to visit, but only orchids were known to tempt male insects with flowers that resemble females.

Allan Ellis of Stellenbosch University and Steve Johnson of the University of KwaZulu-Natal have shown that Gorteria diffusa daisies use the same sexual lure as some orchids, reports New Scientist.

The petals of this daisy vary widely; with some bearing markings that look uncannily like the bodies of female flies.

Ellis and Johnson found that male bombyliid flies tried to copulate avidly with flowers whose petals most resemble female flies.

Ellis and Johnson also tracked how the flies spread pollen. By replacing it with fluorescent powder, they showed that flowers, which elicit the most ardent sexual advances, are also most successful at spreading their pollen.

Males move rapidly between flowers looking for mates, so markings resembling a resting female likely boost visit to a flower. What’s more, amorous males are more active than feeding ones and so spread more pollen.

Anne Gaskett of the University of Auckland who studies sexually deceptive orchids, said the finding might provide the missing link between food- and sex-based strategies used by plants to attract pollinators.

“The study provides intriguing insight into how sexual deception might evolve from the much more common food deceptive system, and how both systems can operate simultaneously,” she said. (ANI)