Beware the Bloodsucking Fly

Due to the recent hot weather the Black Fly (Mosca chupasangre) also known as the Bloodsucker Fly has become more prevalent throughout Spain, with the area of the River Ebro particularly affected at the moment but historical records have been broken in the number of cases registered in the country and If the summer heat continues, there could be more cases during July and August.

The so-called black fly is more closely related to  a mosquito than to a fly. The females are hematophagous and need the blood of mammals as a nutritional contribution for the laying of eggs. They are generally seen between the months of May and October, with most bites happening at dawn and dusk, although they can bite at any time during the day.

Black fly adults are large fliers that can travel more than 20 kilometers on a single flight.

Its sting "causes an intense, lasting and painful itching that can last for weeks"

The jaw of this insect will tear the skin, while releasing an anesthetic and extracting as much blood as possible.

Back in 2018 there were cases of Black Fly bites and warnings in the British Tabloids, where they are know as the Blandford Fly.


Black fly bites leave a small puncture wound, and can result in anything from a slight swelling to a swollen lump the size of a golf ball.

The symptoms of the black fly bite may not be noticed until quite some time after the initial bite. Symptoms include: pain, bleeding, inflammation, swelling, blisters, joint pain and sometimes high temperatures and occasionally allergic reactions.  The effects last on average for one week, with the skin being torn the area can become inflamed and infected so keep the area clean.

Other symptoms may include headache, nausea, fever and swollen lymph nodes. If the itching persists or you have severe swelling, headaches nausea etc, consult a medical professional.

Tips to avoid the sting of the black fly

  • Install mosquito nets on doors and windows in risk areas
  • Avoid walking near the river courses, especially at dusk, where there is abundant vegetation
  • Wear long clothes and long pants
  • Because they are attracted to dark colors, it's also a good idea to wear light-colored clothing, such as khaki, tan, or white.
  • If repellents are going to be used, farmacias can tell us which are the most appropriate and how to apply them.
  • Repellents are basically the same as for mosquito's 


Clean and disinfect the area even if just with soap and water this will help reduce the risk of infection.  Avoid scratching to minimize reactions and apply antihistamine, cortisone or topical steroids to the affected area to help calm the pain.  Applying ice in the area at fifteen minute intervals will also help to to reduce the swelling.

How to differentiate the black fly from the common mosquito?

The black fly is more similar to the mosquito, although it is even smaller than these (it has dimensions of about 3 millimeters).  the females travel great distances to feed themselves; the males, do not stray too far from the water courses and nearby vegetation.

These larvae are deposited in mountain waters and clean mountain rivers where they adhere to the algae until they reach the pupa stage. When they need running water for their development, they also frequent irrigation areas and irrigation channels. They are not found in stagnant pools, as mosquitoes do.

Known infected areas are being treated.

Information on Dangerous insects and creepy crawlies can be found HERE

and non dangerous HERE

If you need Medical Assistance you will find full information on where to go and what to do HERE


0 # Duke 2020-03-14 20:31
Very valuable information,
King regards,
Demir Duke
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0 # Beverley Carlisle 2019-07-23 10:58
I was bit when i was there injuly glad to say its healed great
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0 # Ann Stewart 2019-07-22 22:56
Came home on 12th and bites still not cleared up. My hubby, my son & I always get bitten but this time they ate us alive. Our legs looked awful. My feet swelled up and we stayed away from the pool a couple of days because we were embarrassed. Im I'm glad that i I know what caused it ill I'll be better prepared next time ?
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