Thanks to Jan over at Mud, Gorse and Pines, I now know what the insect is that I am allergic to. It is called the mosca negra or in English, black fly.
- The mosca negra is a recent introduction into Spain from Africa (10 - 15 years) and the two specific types that have been causing havoc are simulium intermedium and simulium ornatum.
- In recent years, over 2000 people have been hospitalised due to suffering severe allergic reactions to the bite of the mosca negra in Catalunya alone.
- Their breeding ground is in flowing clean water, unlike the mosquito which prefers stagnant water.
- After the larvae have hatched, they can spread out as far as up to 50 kms from the site they were born. There is a river in this village which I have not inspected as in recent years it has been re-routed away from the mills they used to feed. However, it is safe to say that my house is not more than 2/3 kms from the river.
In Catalunya is the River Ebro which scientists have now treated with Bacillin Thuringiensis which grows to produce spores that attack and kill the larvae of the simulium.
The Black Fly
The black fly is 2-3 mm across, much smaller than the mosquito and when they bite they draw blood. It is not uncommon to suffer extreme inflammation in the area of the bite, as well as a tremendous itch which can be relieved with a costi-steroid topical application.
They are diurnal and bite during the day, and like the mosquito, it is only the female of the species who needs a blood host.
Their danger cannot be underestimated - a swarm of them killed a calf in Switzerland in 2005.
It is recommended to wear light coloured clothes with long sleeves if you suspect they may be in your area, and to wear an insect repellent. There is some suggestion that DEET-based sprays do not deter them, and that wearing permethrin-soaked clothes might be a better alternative.
From reading several Spanish websites and blogs, it seems that the Spanish insecticide Autun (which contains icaridine) works well, as does a product called "locion hydratante de Natural Honey" which is a Honey Hydrating Lotion.
The black fly is known to live in the US and Canada too, where it is known under various names including buffalo gnat, turkey gnat or white socks. There are very many different species of black fly under the umbrella of the giant Simulium family. They are a serious problem because they spread disease.
The Blandford Fly in England is actually a black fly named Simulium posticatum and the New Zealand Sandfly is actually a black fly fom the Simulium family.