Orchids are known for toying with males. Many species produce female-mimicking perfumes that lure males into spreading pollen. But most insects merely touch down on the flowers.
Gaskett noticed, however, that dupe wasps (Lissopimpla excelsa) spent a lot of time around tongue orchids. Many left a visible blob on the flower after flying away. "We decided to check if they were wasting their sperm on the flowers,"
Next, Gaskett set up field experiments to determine how often the wasps "had sex" with the flowers – and whether they eventually learned from their follies.
On first visiting a tongue orchid, nearly three-quarters of wasps left sperm on the flowers. But after repeated visits, most insects stopped copulating with the flower.
"They are perhaps not really educated about what a real female looks like, and they make a bad decision," Gaskett says.
Gaskett thinks that the peculiar reproductive lives of the wasps might explain why males have not evolved to discriminate against orchids. Female wasps reproduce asexually – that is, without male help – to spawn males, while sexual reproduction between both sexes produces only females.
"If you are the female and you miss out on mating because your male is out with an orchid, you can still reproduce," she says.(from New Scientists)
ein hod posted a video - ein hod posted a video הקרב על הוועד - טריילר סאטירה פוליטית שנוצרה על רקע המתיחות והאלימות שליוו את מערכת הבחירות של 1984 ועל תוצאותיה הפוליטיות והחברתיות....
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