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Mailes prefer flower's scent to female wasp's. (Better than real).

In an extreme case of sex fakery, an orchid produces oddball chemicals that mimic a female wasp's allure so well that males prefer the floral scents to the real thing, scientists say. This plant's come-on is different from that of a related orchid that flirts with bees.

The Mediterranean orchid Ophrys speculum manufactures whiffs of the same scent that the female wasp Campsoscolia ciliata does. The flower misleads male wasps into mating attempts that benefit the plant by spreading pollen, explains Manfred Ayasse of the University of Ulm The University of Ulm (German: Universität Ulm) is a public university in the city of Ulm, in the South German state of Baden-Württemberg. The university was founded in 1967 and focuses on natural sciences, medicine and the engineering sciences, mathematics/ economics and  in Germany. He and his colleagues have now identified the attractants as chemicals not previously known in plants. The orchids produce them more abundantly than female wasps do, and males prefer the stronger bouquet, the researchers say in an upcoming Proceedings of the Royal Society Proceedings of the Royal Society is a scientific journal published by the Royal Society of London.

Today, the Royal Society publishes two proceeding series:
  • Series A, which publishes research related to mathematical, physical and engineering sciences
 of London B.

This finding adds to the growing respect for the powers of deceptive orchids, according to according to
1. As stated or indicated by; on the authority of: according to historians.

2. In keeping with: according to instructions.

 Ayasse. Biologists had previously concluded that the plants make only mild attractants that males neglect once females appear. Last year, however, scientists found that an Australian orchid releases a scent that attracts inexperienced male bees as well as the actual female scent does (SN: 7/27/02, p. 56).

Several hundred orchids have been identified worldwide that use sexual deception to attract pollinators, says coauthor Florian P. Schiestl of the Geobotanical Institute ETH eth  
Variant of edh.
 in Zurich.

With brushy red hairs, the O. speculum blooms look vaguely like the wasps that pollinate pol·li·nate also pol·len·ate  
tr.v. pol·li·nat·ed also pol·len·at·ed, pol·li·nat·ing also pol·len·at·ing, pol·li·nates also pol·len·ates
To transfer pollen from an anther to the stigma of (a flower).
 them. The flower produces 100 to 150 volatile compounds, but tests by several scientists had failed to figure out which ones matter, says Ayasse. He and his colleagues hitched a gas chromatograph gas chromatograph
An instrument used in gas chromatography to separate a sample of a volatile substance into its components.
, which separates scent components, to equipment that measures nerve impulses in insect antennae. With this setup, the researchers identified the 10 compounds that the male antennae detect.

When the researchers offered whiffs of these substances to the wasps, only a few related compounds inspired males to start attempting to mate. One chemical, 9-hydroxydecanoic acid, had been previously described only in honeybees.

The scientists next set out pairs of dead females, one with the scent from a flower blown over it and the other with the scent from a real female wasp. Males responded to the floral scent with more than twice as many attempts to mate as they did to the true sex lure.

This orchid's chemical seduction takes the opposite strategy from that of a species in the same genus that the team had analyzed earlier (SN: 7/3/99, p. 11). That study had found that Ophrys spegodes relies on a specific blend of more than a dozen common chemicals rather than a mix of a few rare compounds. Finding sister species that take such different approaches indicates that "the [orchid] system is very flexible," Schiestl says.

Says pollination pollination, transfer of pollen from the male reproductive organ (stamen or staminate cone) to the female reproductive organ (pistil or pistillate cone) of the same or of another flower or cone.  biologist Elizabeth Elle of Simon Fraser University Simon Fraser University, main campus at Burnaby, British Columbia, Canada; provincially supported; coeducational; chartered 1963, opened 1965. The Harbour Centre campus in downtown Vancouver opened in 1989.  in Burnaby, British Columbia “Burnaby” redirects here. For persons sharing this surname, see Burnaby (surname).
Burnaby, British Columbia, Canada, is the city immediately east of Vancouver.
: "Think of it as an arms race. At the moment, the plants are ahead."
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Title Annotation:orchids
Author:Milius, S.
Publication:Science News
Geographic Code:4EUGE
Date:Feb 1, 2003
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