The bed bug of the genus Cimex lectularius is up to six millimeters in size and feeds preferably on the blood of humans. Credit: Harraca et al., BMC Biology
Vorlesen Bed bug larvae know how to defend themselves against the intrusiveness of mating male males: Swedish researchers have shown how the little ones by a cocktail of scents for the aggressive males make unattractive. For immature larvae, the persistent mating behavior is a danger because their body is injured by the mating. Bedbug males are not picky? They climb every fellow conspecific that crosses their path, taking care of neither age nor sex. The discovery of the defense scents could be used for the development of control strategies against bug plagues. The act of mating is a rabid process in bedbugs, which the researchers around Vincent Harraca of the University of Lund call traumatic: The male of the bed bug Cimex lectularius pricks a hole in the female during mating to bring its seeds directly into the body, However, the male not only mates females. It pounces on every individual of a certain size and inseminates larvae due to this undifferentiated partner choice, say the researchers, because in the last instar larva the immature animals are about the same size as the bed bug females. While the females' body has adapted to the coarse nature of mating, the larvae are severely injured by the bite.

"In order to protect themselves, the larvae specifically target fragrances that signal to the male that it should deposit its seeds elsewhere, " explains Harraca. These fragrances are a special type of alarm pheromone that the male can pick up on his or her probes via odorant receptors.

To better understand the chemical fragrance communication system, researchers investigated the exact effect of this anti-mating fragrance. To do this, they smeared the stink glands of the larvae with nail polish so that the animals could no longer secrete pheromones. The thus prepared odorless larvae were mated in the episode just as often as adult females of males. In order to investigate the effect of the defense odor even more closely, the researchers scented even the sexually active males themselves. Result: The males mated to this scent attack rare than before.

"The chemical communication system of bed bugs is being researched. So far, it was assumed that alarm pheromones are used exclusively to ward off predators, "explains the study director. The results of the scientists show that the odor signals have many more functions and are also used against unwanted mating attacks. This discovery could be used to deliberately disrupt the mating of bed bugs and thereby curb the current growing population. According to experts, the unpleasant parasites in Germany are increasingly causing unpleasant stings. display

Vincent Harraca (University, Lund) et al .: BMC Biology, Online Preview, September 2010, Vol.8. doi: 10.1186 / 1741-7007-8-121. dapd / science.de - Kristina Abels

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