High temperatures intensify pests and plagues in Spain

by Lorraine Williamson

MADRID – We wrote on Thursday about the mosquito (Mosca Negra) whose plagues are increasing after last week’s heatwave. Other insects and animals are also more common after periods of extremely high temperatures. 

Mosquitoes, ticks and the tickling mosquito are some of the species that thrive in the Spanish summer. The rise in temperature during heatwaves promotes the exponential increase in their populations. In many cases, this makes them harmful to humans. 

Milagros Fernández, pest control expert confirmed this to EFE. Fernández was also Director-General of the National Association of Environmental Companies (ANECPLA). Due to the rise in temperatures this summer, the populations of pests are increasing sharply. 

“Excessive increase” of tickling mosquito 

The heatwave that swept the country last week will cause an “excessive increase” in the population of the black fly. They are also known as the tickling mosquito, pests that reproduces on riverbanks with a corresponding increase in attacks on humans. 

The mosquito “does not transmit disease”, but Fernández points out that its bite can be “spectacular”. This is because it breaks the skin and can lead to infections and allergic reactions that in some cases require hospitalisation. 

The good weather in Spain also means many people are outside more, which also increases the chance of being bitten. In addition, those outdoor activities lead to a greater amount of waste in different places. And that is precisely what attracts mosquitoes. 


Another animal that has spread this year is the tick, whose numbers continue to grow. Not only in Spain but all over Europe. 20 species of ticks have already been counted in Spain. In general, their bite is painless and causes few symptoms: redness, swelling or a small sore on the skin. The greatest danger from ticks is they can carry and spread Crimean Congo haemorrhagic fever and Lyme disease. That is if they are themselves infected with the bacterium Borrelia burgdorferi. However, Fernández notes that Crimean-Congo fever was only first seen in Spain in 2013.  And has since infected nine people, three of whom have died. 

“The tick is one of the most dangerous parasites for humans,” Fernández warns. It is true, however, a tick must have bitten an animal infected by one of these diseases before it can pass to a human. In Spain, the transmission of the Crimean-Congo fever is not that bad “. Fortunately, the Crimean-Congo haemorrhagic fever is not widespread here. However, with the exception of some wild animals in areas in Extremadura, Castilla y León, Castilla-La Mancha and Madrid who are infected with it.” 

Cogesa Expats


Mosquitoes are also a threat, especially those of the genus ‘Culex perexiguus’ – better known as tiger mosquito due to its striped markings – are vectors of the West Nile virus that caused 77 cases in Spain in 2020 – 40 confirmed and 37 probable – of meningoencephalitis. encephalitis, according to the National Centre of Epidemiology (CNE). 

Wasps and bees 

The bites of these insects increase significantly in the summer when they are most active and people spend more time outdoors. In addition, the Asian wasp has also been found in Spain for several years. This is an invasive species that is now widely seen in areas along the Cantabrian coast and Galicia. The Asian giant hornet has also been spotted in Spain. This one is even more dangerous and aggressive than the Asian wasp. 

 It is especially important for people with allergies to their poison to be careful. According to the College of Pharmacists in Spain, 3% of the population is allergic to the venom of wasps or bees. Every year 3 to 4 people die due to an allergic reaction in Spain. Currently, the most effective treatment for allergy sufferers is the vaccine, which has a success rate of nearly 95%. 

The rise in temperatures is one of the main drivers of this increase in West Nile virus cases. Juanjo Carmona, WWF‘s Doñana coordinator, reports the virus also reached Spain years ago but did not “find the conditions to reproduce”, causing it to quickly disappear. 

Both Carmonda and Fernández consider proper “epidemiological surveillance” to be key to reducing this increase in the number of disease transmission cases. This makes it possible to know when an animal has a certain disease, to raise the alarm level and to keep infections under control. 

The person responsible for the subject of climate change at Ecologistas en Acción, Javier Andaluz, indicates that not all insect species benefit from the increase in temperature. He points to species that have “certain problems” as a result of the imbalance in the flowering cycles of the plants they feed on and disappear. 

Pests, insects and other animals

Andaluz has no doubts that “other animals that were previously less common will come and stay on the peninsula”. Where they used to disappear in the winter, they will now be able to survive the winter months due to higher temperatures. An increase in the number of pests of these species is then a logical consequence. 

Baycrest Wealth

You may also like