The (scientific) siege of the mosquito carrying the passerine “plague”

Animal deadliest in the world It measures between three and seven millimeters, lives near water (the more stagnant the better), feeds on blood (but only in the adult stage) and is unusually fertile. Its scientific name Culex pipiensAlthough the best known is the one that lives at home, the common mosquito, an insect that few people pay attention to except when they bite or bother with their buzzing, but which is the largest known vector of disease, a real emissary of disease. death.

The common mosquito is also the main culprit when malaria (more specifically, avian malaria) wreaks havoc among birds. plague who travels through the air and whose favorite victims are the sparrow.

Three out of ten sparrows are infected with avian malaria. It is not fatal like malaria, which affects humans, but it is chronic illness which makes reproduction significantly more difficult, which weakens the bird and makes it much more vulnerable to predators. It doesn’t kill him, but… And the sparrow is not the only one who suffers from this.

An investigation carried out by the Doñana Biological Station (EBD), dependent on the Supreme Council for Scientific Research (CSIC), with the collaboration of the University of Granada and the Provincial Council of Huelva, found some keys which can help protect the sparrow (and other birds) from Culex pipiens and, by the way, avian malaria.

The study is led by Italian biologist Martina Ferraguti, Ramon y Cajal researcher from EBD Dognana and passionate about the mosquito – “they’re very cool,” he defends with a laugh – to which he has already devoted his doctoral dissertation and to which he has continued research throughout his career.

The just-completed project began in 2013 (with a gap of several years), and the researchers found, among other things, that the common mosquito with the highest prevalence of the species Plasmodium relictumThe parasite that causes malaria does not live near rivers or swamps, and its preferred habitat is natural environmentin which there are no people or livestock, like in forests.

They also found evidence that of the thirteen lineages (types) Plasmodium relictumstudied avian malaria parasites, most dangerous This is the so-called syat05, which is also the most abundant among the 37 host species (bird species) studied.

Magazine iScience just published all the details, including conclusions, in extensive article -signed by Ferraguti, Josue Martínez de la Puente, Santiago Ruiz, Ramón S. Soriguer and Jordi Figuerola – which provides tools, says the CSIC researcher, to narrow down those responsible for the transmission of malaria between birds and therefore reduce the damage that it affects many species such as the sparrow.

Direct relation Between the decline in sparrow numbers and avian malaria, the problem is not new and there are studies such as the study carried out between 2006 and 2009 by scientists from the Zoological Society of London, the Royal Society for the Protection of Birds, the British Trust for Ornithology. and the University of Liverpool, which confirmed the presence of the disease in 74% of urban sparrows in London.

The novelty here, as Ferraguti emphasizes, is that it clearly defines where and how to deal with Culex pipiens.

They were studied, explains the Italian biologist, three types of habitat. In addition to natural, a distinction is made between rural (where there are livestock and humans) and urban, and it is concluded that after natural, the highest prevalence of the avian malaria parasite is urban and, finally, rural.

To achieve these results, the Ferraguti team hunted16,574 common mosquitoes in three provinces in southern Spain: Huelva, Cadiz and Seville, including the Doñana National Park.

How can you catch so many mosquitoes? Well, Ferraguti parts, with specially designed traps called BG-Sentinel and which, speaking in general terms and without going into special technical details, are a kind of basket with a fan in the center and dry ice, which when dissolved releases CO2 , animal breathing simulationand “that’s what attracts mosquitoes.” Because, contrary to urban legends, this is not the one sweetness This insect seeks CO2 from the blood, and there are people, says the CSIC researcher, who, due to their metabolism, emit more than others and are therefore a magnet for bites.

The 16,574 mosquitoes caught in Huelva, Seville and Cadiz were then grouped into 768 groups and these groups were analyzed in laboratories to obtain all the information, data that allowed them to identify the most dangerous ones.

The importance of this study and its findings suggests that they will be the protagonists in International Congress Next November, Colombia will celebrate the fight against malaria parasites in the wild. This is the most important non-human malaria event observed in the world.