Reading aloud With their loud whirring mosquitoes reveal themselves in the approach to their victim. But why has evolution not expelled the bloodsuckers from this alarm long ago, who instigates in defense? Because the sex drive is stronger than hunger: British scientists have found with sensitive microphones that the females and males of the same Malariamücken-type together when the frequencies of their wing beats harmonize in flight. With this selection, the pest spirits prevent mating with alien animals and thus preserve their genetic diversity, through which the carriers of the malaria pathogens can adapt quickly to environmental conditions. Of the more than 420 species of Anopheles mosquito, ten percent are potential malaria carriers. Fixed on humans and thus particularly dangerous are the seven species of the African Anopheles Gambiae, which can not be distinguished on the basis of external characteristics. Surprisingly enough, this genetic diversity has been preserved, although Co-study author Ian Russel from the University of Greenwich in Burkina Faso has even discovered two of these mosquito species in one swarm. The animals find the species-appropriate sex partner with a trick: they recognize themselves by their flight noise.
In earlier studies, Gibson had already found in animals of different sex, the synchronization of buzzing noises. The mosquitoes hear neither the own nor the "song" of the partner, but they perceive only dissonance. The animals then try to reduce them by another flapping frequency. "It even works if they're up to four notes apart, " reports Russel. "They create a perfect harmony, but only we humans can hear." The pitch of the pitch does not succeed in the same sex and, as now proven, in unequal types. The scientists emphasize the power of this highly developed perception of insects: humans can only distinguish African mosquito species by genetic analysis.
Cédric Pennetier (University of Sussex, Brighton) et al .: Current Biology, online pre-publication ddp / science.de? Rochus Rademacher