The role of pheromones

2020-08-19 13:02:06

Howard Ensign Evans wrote that the sex lives of cockroaches reveal the secret of their success in keeping the world populated with their kind.


Indeed, cockroaches are structurally built to be reproductive wunderkinder. While it is sometimes necessary for the male cockroach to have physical Contact with the female before interest in mating is sparked, there are instances in which the female sends out a pheromone that attracts the male even if hes not in her immediate vicinity.

For example, in the American cockroach, the female launches her pheromone tell the male to prepare for sexual intercourse. He approaches, facing her head-on. The two then begin to touch their antennae together in a method Evans calls fencing.

 Following a brief period of antennal foreplay, the male turns away from his love interest. He then raises his wings to release his own sex chemicals that drift from the glands on his back. If the female is still inclined to mate, she will climb on the males back and begin to eat his chemical exudate. These chemicals induce her to assume a mating posture. When she does so, the male unmasks his genital organs, which he useslto attach himself to her. Says Evans, She is hooked very literally for the hour or two required for copulation.

In the animal world, the male who succeeds in his sexual advances often exhibits the most masculine traits. In the Tanzanian forest cockroach, this can occur to a chemical extrembut it doesnt guarantee necessarily that the guy will get the girl. University of Kentucky entomologists found that some male cockroaches of this species secrete high concentrations of a pheromone component that puts them in charge and sends the submissive males, whose quantity of the pheromone chemicals not as potent, far down the ladder of superiority. When in the company of submissive males, the dominant cockroaches will kick, bite, and run into them in attempts to knock them over.

The scientists studied the molecular structure of the pheromone in question and found that it is composed of three different chemicals: two that lead to aggressive behavior and one that is responsible for submissive behavior, or groveling, as the entomologists describe it. When the dominant pheromones were placed on the heads of the submissive males, they, too, became aggressive and bullying. But, the question to ask is this: How might the male cockroach benefit at all from a groveling pheromone? One theory is that the females are put off by male bullies, even though they display the usually desirable masculine traits, and that the groveling pheromone helps to temper that behavior, which the females perceive as dangerous to themselves and to their kin.
Hamster Dances
The male golden hamster will not mate if he cannot detect the pheromones from the female of his species. A series of chemical transactions must occur before mating begins. First, the fe- male in heat will emit a pheromone announcing she is ready to mate. In response, the male greets the female by sniffing the scent glands on her head. She begins to warm up into a posture that broadcasts her intent to submit.

Following the fernales yes signal, the male will start to lick her ank; in doing so, he homes in on another scent gland located on the side of her body. From there, he moves to her rear, still licking and sniffing. Only once he detects the special pheromone that directs him to mount her does he do so.