Exotic Orchids Deceive Unsuspecting Wasps
Posted on: Thursday, 8 May 2008, 22:40 CDT
Researchers in Australia reported this week that orchids that imitate female wasps lure male wasps into wasting valuable sperm, providing a dual benefit to the flowers by assisting in their own reproduction and creating additional male pollinators in the process.Over time, some of nature’s most exotic orchids have evolved their elaborate shapes to attract insects that unknowingly collect and transfer pollen in their attempt to mate with the flowers.
"The effect of deception on pollinators has been considered negligible, but we show that pollinators may suffer considerable costs," wrote Anne Gaskett of Macquarie University in Sydney and her colleagues in a report about the findings.
"Insects pollinating Australian tongue orchids (Cryptostylis species) frequently ejaculate and waste copious sperm," they wrote.
The wasps suffer not only inconvenience, but also harm .
"Male pollinators can prefer orchids to real females, prematurely end a copulation with a real female to visit an orchid, or be unable to find real female mates among false orchid signals," the researchers wrote.
"Unquestionably, producing sperm, ejaculate, or seminal fluids is costly for many animals. The energetic demands of sperm production can result in reduced body mass, a shortened life span, or limited lifetime sperm production," the researchers explained.
The orchids’ deception works in their favor in more ways than one.
"We also show that orchid species provoking such extreme pollinator behavior have the highest pollination success," they added.
"How can deception persist, given the costs to pollinators?"
The scientists discovered wasps that frequent these flowers are haplodiploid species, which means female offspring are produced through sexual unions but male offspring are produced asexually. Bees, ants and similar species also use this method of reproduction.
"Therefore, female insects deprived of matings by orchid deception could still produce male offspring, which may even enhance orchid pollination," wrote the researchers.
Gaskett's team examined flowers after wasps visited them and found the deceived wasps did indeed eventually wise up.
"With experience, male Lissopimpla excelsa wasps become less likely to copulate with and pollinate sexually deceptive Cryptostylis orchids," they wrote.
The study was published in the journal The American Naturalist.
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Macquarie University
The American Naturalist - Full Report
Source: redOrbit Staff and Wire Reports
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