Biologists have found that the Asian ladybug conquer Europe and North America managed with the help of parasitic fungi. Insect infect their competitors, while remaining intact.
These are the conclusions of German microbiologists from the University of Giessen, who published its findings in the next issue of the journal Science.
In Europe, ladybug species Harmonia axyridis or harlequin ladybird, originally was imported from East Asia as a weapon to control aphids. But soon the uncontrolled multiplication of insects has led to a reduction of native species of ladybugs. If you are going to hibernate in huge flocks and proinkaya in the house, H. axyridis provoke allergies in humans. In addition, this type of ladybugs significantly spoil the taste of wine, getting into the harvest.
In order to establish the cause of the success of "Conqueror", the researchers compared the genomes of H. axyridis and Coccinella septempunctata - known to all semitochechnyh ladybirds. It was found that in the genome of H. axyridis contains many genes of antibiotics, whereas semitochechnoy ladybug, there is only one such gene. Antibiotics, as shown by scientists needed Harlequin ladybird to control present in the cells of the organism microsporidia.
Microsporidia (Microsporidia) - it’s mushrooms, intracellular parasites that live in the bodies of invertebrates, fish and other animals. Experts have found that microsporidia, which infected H. axyridis, are very similar genetically to the genus Nosema, which causes the development of diseases in bees. A strong immune system protects H. axyridis from the negative impact of microsporidia.
Meanwhile, other types of ladybirds are killed by these microsporidia. This has been proven by scientists in the experiment, introducing the ladybirds injection of the parasite, which was isolated from the hemolymph of H. axyridis. This parasite in the wild ladybugs are infected by eating the eggs and larvae of its Asian competitors. Most likely, the association with microsporidia and helped H. axyridis displace other species.
Soon H. Axyridis, as the researchers will be able to conquer the whole world, because it is adapted to life in a variety of climatic conditions. "I do not see a way to stop these insects, in my opinion, it is too late to attempt to do anything," - said the chief author of Heiko Vogel.