Spanish experts warn of 'plague' of black flies after the heat wave

This insect does not sting, it bites tearing the skin and it is extremely painful. According to Anecpla, this fly, measuring just six millimetres long, «in a swarm can kill mice or birds and, in the case of people, its attack usually causes swelling and wounds that can last more than a week.

The bite of a black fly can lead to «very alarming infections and allergic reactions, which in some cases require hospitalisation», explains the general director of the National Association of Environmental Health Companies, Jorge Galvan.

«High temperatures are one of the main factors for producing a spike in the black fly population», clarifies Galván. «Its life cycle, which can be completed from a few days to several months, can be reduced by half when it is very hot, as happened last week, thus producing a boom and, consequently, an increase in the number of bites», he adds.

The black fly reproduces in riverbeds, especially in those that are clean and specifically in floating vegetation, which is exposed when the water level begins to drop.

«It is not an invasive species, the black fly is indigenous, but for several years spikes have been observed in its attacks on humans. Hence, we see it necessary to deal with this plague that it is becoming a public health problem, « says the general director of Anecpla.

The black fly begins by inoculating a small dose of anaesthetic into the victim, which allows it to bite without the individual noticing. The saliva is what usually causes severe allergy symptoms and severe pain in the area. The final effect is a welt, several centimetres across, that usually bleeds, accompanied by a swelling that can last up to a month.

The national association of environmental health companies advise not to scratch the bite, since it can worsen the wound and cause it to become infected. Instead, it recommends applying ice to reduce inflammation, or an ointment with a mild corticosteroid. The experts say that if the reaction to the bite worsens people should visit the nearest health centre or hospital.

Anecpla has issued recommendations to avoid being a victim of this insect this summer:

- Dress in light clothing, without bright colours that can attract swarms.

- Avoid walking alongside rivers or areas near them, especially in the late afternoon.

- Install mosquito nets on doors and windows in at risk areas.

- Avoid the accumulation of pools of water outside the house and keep the water tanks covered.

- Check the drains.

- Use certified repellents (especially those containing citronella).

- Contact professionals.