"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."
"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. 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."
Thus wrote Anne Gaskett of Macquarie University in Sydney and her research colleagues in
The American Naturalist recently.
It turns out that there are certain species of orchids that have evolved in such a way that they mimic or resemble female wasps' most important features (in the opinion of male wasps, that is). Orchids have been described as the world's sexiest flowers, and apparently there are male wasps that do agree with that opinion.
The researchers futher point out that these orchids are so sexy that the male wasps sometimes come to prefer them to the "real thing" (does this have implications for certain human male sexual behaviors?). According to the researchers, this could wind up increasing the male wasp population, since female wasps can reproduce male wasps asexually but cannot reproduce female wasps without having sex.
But far more relevant to the orchids, getting wasps to ejaculate helps the flowers to pollinate more. The "tricky" flowers coat the horny wasps with their pollen. When the wasps visit other like flowers, they pollinate them.
The type of orchids that most strongly attract the wasps are called "tongue orchids" and some biologists believe that they appear to have evolved quite specifically to dupe male wasps into doing a great deal of their pollinating for them.
Field researchers headed up by Gaskett, when they first came to suspect the close connection between the tongue orchids and the wasps, braved such things as spiders, snakes, leeches, bushfires, sunburn, and dehydration in order to collect hard evidence about what was going on. Their subsequent data analysis proved their suspicions correct.
What's more, the researchers now know that there are approximately 200 insect species that get tricked into having sex with orchids, and over 90% of them have females that can reproduce asexually.
Gaskett believes that this dynamic interaction could be acting as a driver of both orchid and wasp evolution. The orchids will need to evolve more in order to keep on tricking the male wasps (some of whom eventually figure out the deception), and the wasps will need to evolve more intelligence in order to better figure out the duplicity of the orchids and possibly other flowering plants.
