How flies fall for daisy’s deceptive charms

Cape Town - The beetle daisy, Gorteria diffusa, has found a way to deceive male bee flies, making them think they are visiting a female fly when they are in fact just pollinating the flower.

These were the findings of a research team from Stellenbosch University.

File photo: GeneWatch UK said many maggots may also die inside the growing olives, posing a risk to human health. Credit: AFP

“The special markings or ornaments on their petals closely resemble female insects and so attract amorous, pollinator males,” project supervisor Allan Ellis said in a press statement from the university. “This type of sexual deception was previously thought only to have been mastered by orchids.”

The bee flies are so named because they pollinate flowers.

Marinus de Jager, a PhD student in the Department of Botany and Zoology, told the Cape Times that they tested different characteristics of the flower by building flowers made of epoxy. The flowers were placed in 1m cubed boxes and flies were allowed to visit. For each model they measured the effect of different characteristics such as scent, look and feel on the different sexes of the flies, Megapalpus capensis.

“We found that there was a large difference in the preferences of the male and female flies,” De Jager said. “Females prefer the simplistic plant with simple black spots.”

De Jager said the males preferred the more elaborate patterns on the flowers with UV highlights and three-dimensional patterns.

Interestingly, these highlights were the same as those found on the bodies of female flies. He added that when males landed on the flower they transferred more pollen than female flies. This led them to conclude that the flower had evolved to attract males, therefore increasing its chances of survival.

De Jager and Ellis have published their findings on gender-specific preferences in the journal Functional Ecology. - Cape Times