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Disease carriers Infertile males for the fight against tiger mosquitoes
Scientific research has shown that in recent years various tropical mosquitoes have spread in Germany, including the Asian tiger mosquito. The insects can transmit dangerous diseases. Now infertile males should help to fight the mosquitoes.
Asian tiger mosquito is a security risk
Although mosquito bites are generally harmless in this country, meanwhile mosquito species have been detected in Germany, which can transmit dangerous infectious diseases. Especially the increasing spread of the Asian tiger mosquito is considered with concern. This insect is considered a flying security risk. Experts now report that infertile males should help combat tiger mosquitoes.
In recent years, various tropical mosquito species have spread in Germany. Researchers now rely on sterilized males in the fight against Asian tiger mosquitoes. (Image: mycteria / fotolia.com) Spread several exotic mosquito species in Europe
"Benefiting from globalization and global warming, the introduction, establishment and spread of exotic mosquito species in Europe has increased in recent years", wrote the National Commission of Experts on "Mosquitoes as Pathogens" last year in a recommended course of action.
"Many affected countries (such as Spain, Italy, France, Belgium, the Netherlands) regularly take local or regional control measures to prevent the establishment and spread of the species and / or the transmission of pathogens," it said.
As the news agency dpa reports, scientists are testing the use of sterilized males in the fight against the Asian tiger mosquito in Germany.
Biologist Norbert Becker told the German Press Agency in Speyer that females copulating with these males did not have viable progeny.
"The females get pregnant, but they have stillbirths."
Becker is the Scientific Director of the Community Action Group for the Control of Snaring Plague (KABS) and Director of the Institute of Dipterology, which fights the tiger mosquitoes.
Habitat of the tiger mosquito with infertile males "flood"
According to experts, the Asian tiger mosquito can transmit more than 20 types of virus, including dangerous variants such as dengue fever, which can be fatal to people who are weak.
In Italy, the animals have been around for some time. From there they came in recent years on freight trains and trucks along motorways to Germany.
According to Becker, there is now a plan to "flood" the habitat of the animals - in addition to conventional control - with infertile males..
"We have to consider all possibilities to get rid of this animal," says the biologist. "And there are no half-baked solutions, because there is only a massive fight."
Hatching rate dropped by 15 percent
According to the information, the insects are sterilized in Bologna (Italy). The treated animals could then still compete with wild males, "but the sperm is 99 percent not okay," said Becker.
From there, the mosquitoes are brought to Germany and released - last summer, a total of eight times. At that time, the hatching rate had dropped by 15 percent.
But that's not enough: "Fighting plus reducing the hatching rate would, according to our calculations, lead to the collapse of the population," says Becker. This year, therefore, the suspension began much earlier and the number of sterilized males increased.
At present it is still unclear whether enough mosquitoes can be bred and treated at all. But this would be necessary, because a previous experiment has shown that the use of too few animals does not work.
Becker recalled in the dpa message to a project in the 1980s, when 30,000 animals were exposed, where probably a billion slipped. "And you did not notice anything at all." (Ad)