The Blandford Fly (sometimes called blackfly) is a small 2-3mm insect usually found in East Anglia, Oxfordshire and Dorset. Blandford Fly bites are most common during May and June. They often occur on the legs and can be very painful. The effects of the bites on humans range from small blisters to large (up to 22cm diameter) haemorrhagic lesions, which can produce intensely painful stabbing sensations. The saliva of the fly, which passes into the wound, often causes severe irritation, pain, swelling and blistering. Secondary infection of the lesions can also occur.
The Blandford Fly first came to the attention of public health officials in the 1960s. In a four-week period during the spring of 1972, 600 people were estimated to have visited their doctors in Blandford, Dorset to be treated for insect bites, hence the name The Blandford Fly.
The females require a blood meal before they can lay their eggs – humans and dogs seem to be particularly favoured and they normally bite during the day. Having had a blood meal the female must wait for its 200-300 eggs to mature before returning to a damp and shady spot, such as a river bank. The eggs adhere to soil particles in moist, humid conditions. If you need advice on fly control seek advice from a pest control expert.
What to do if you get bitten by the Blandford Fly
An insect bite often causes a small lump to develop, which is usually very itchy. A small hole (the actual bite) may also be visible. The lump may have an inflamed (red and swollen) area around it that may be filled with fluid. This is called a weal. Insect bites usually clear up within several hours and they can be safely treated at home.
If the area becomes swollen, sometimes spreading to another area, see a doctor immediately. The bite may have become infected or you may have developed a sensitivity.
The NHS advices that if an insect bites you, you may become ‘sensitive’ to its saliva. This means that if you are bitten again by the same or a similar species, it can provoke a local reaction. A local reaction is a reaction that is confined to the area of the bite.
For example, you may develop:
- an itchy papule (lump)
- an itchy weal (an inflamed, fluid-filled area)
This may last for several days and the severity of the reaction will depend on your level of sensitivity.
If you are very sensitive to an insect bite, you may experience anaphylaxis (also known as anaphylactic shock). This is when your immune system (the body’s defence system) reacts badly to the insect bite. However, anaphylaxis after an insect bite is rare. You are more likely to have an allergic reaction if you are stung by an insect.
It is important to know the symptoms of a severe allergic reaction. If you or someone you know is bitten or stung by an insect and experiences a severe reaction, emergency medical treatment will be required.
Symptoms of a severe allergic reaction may include:
- wheezing or difficulty breathing
- severe itching or a blotchy rash over many parts of your body
- severe swelling that may be visible in your lips or tongue
- nausea (feeling sick)
- chest pain
Call 999 for an ambulance if you or someone you know has these symptoms after being bitten or stung by an insect. Simple precautions like wearing long sleeved shirts and trousers will act as a deterrent to getting bitten by the Blandford Fly. Stay away from clouds of flies on river banks because they can bite.