Tiger mosquito bites cause havoc in many areas of the Mediterranean coast in summer. An invasive species that is here to stay and in the case of the Valencian Community, it is estimated that it is already present with its buzz in 85% of the municipalities in its territory.
Control of this insect has become a priority, and not only because its bites are more painful. This species can tolerate more 20 infectious diseases coming from other latitudes, some of them are as dangerous as dengue fever, malaria or the West Nile virus, which already broke out in Andalusia a few years ago.
The mobilization to combat this plague prompted the Generalitat of Valencia to begin to tackle this task. one of the largest sterile insect production facilities in the world. This year its facilities will produce 12 million sterile male tiger mosquitoes. In a strategy reminiscent of the legendary Troy horseThe goal of these insects is to stop the hitherto unstoppable spread of their own species. Sterile males mate with females, but without fertilizing them, the eggs they incubate become nonviable and do not create new offspring. These Male tiger mosquitoes do not bitegiven that only women do this.
Until December, the Ministry of Agriculture plans release all those millions of mosquitoes in the parks of the five major cities of Valencia, since it is in these areas that the tiger mosquito is concentrated in the greatest numbers. In addition to the capital of Valencia itself, where up to 1.3 million men will go out 2-3 times a weekthese insects began to spread into Castellon, Torrent, Paterna and Sagunto.
A technique in which the Valencian Community is a pioneer thanks to its many years of experience in combating one of the biggest threats to native citrus trees: fruit fly or ceratitis capitata. To deal with this pest, which threatened one of the region’s most exported products, the Ministry of Agriculture became one of the leaders in the field of so-called sterile insect technology (SIT), and it has one of the three largest biological plants to do this. insects in the world, along with others existing in Guatemala and Argentina, which is located in Codete de las Fuentes and operates the public company Tragsa.
At the moment produces 11 billion sterile male fruit flies per year and is already receiving inquiries from other countries interested in importing this biological solution, which also avoids the use of pesticides and other chemical products.
From breeding to automated screening
When it comes to mosquitoes, the first step in breeding them is to capture wild males and females, which are used to kill the mosquitoes. playback based at the Valencian Institute of Agrarian Research (IVIA) in Moncada. It is here that this natural process takes place and the developmental phase of the larvae is controlled, after which selection of males and culling of females.
During this process, when they are still pupae in the water, each They differ in their size, because females are older than males, according to Vicente Dalmau, head of the Plant Health Service of the Generalitat. To improve and speed up these rejections on an industrial scale, a machine developed by the department itself is responsible for automating the selection.
Once the male tiger mosquitoes are separated, at the Caudete bioplant they are irradiated with gamma rays. A process that also requires prior research and science, as this should be enough to sterilize without affecting other functions. Hence, due to the short life cycle of mosquitoes, several times a week they are released into designated areas, usually parks, where the largest number of individuals are concentrated, since they have breeding advantages, such as water for irrigation systems and the vegetation itself.
“To test its effectiveness, we carried out a pilot test in two neighboring municipalities, Polinha del Suquer and Albalat, in order to compare the effectiveness of one in which the release was carried out and another in which it was not,” says Agricultural Technician .
The results of these tests, which were later extended to other areas, reduced the number of tiger mosquitoes by up to 70%, so it is considered an effective method, especially in densely populated areas where the risk of contracting diseases through bites is higher. A new way of life with invasive species that, due to high temperatures and climate change, seem to have established themselves in much of the Mediterranean and southern Spain.