What is a gadfly

Gnids belong to the order Diptera and are medium to large-sized species with strong and soft hairs. They are often called cow rainbows. Commonly known as "blind fly" or "blind fly" in the northeastern forest area, it has a large head, hemispherical, or slightly triangular. The compound eyes are very large, and some males are connected or separated from the eyes; the branches are often hairy, and often have green, red and other metallic flashes; the single eye sometimes disappears. The tentacles are either long or short, mostly extending forward, with two distinct segments at the base, and 3-8 segments at the end healed into a horn shape. The mouthparts are suitable for stinging and absorption. The lower jaw is broad-leaf-shaped; the lower jaw is 2-segmented and hairy; the upper jaw is strong; the lower lip or beak is straight and short or slender. Big hairy breasts. The wings are large and transparent, or may be colored. There are two submarginal chambers, five posterior chambers, the basal chamber is large, the gluteal chamber is generally closed, the anterior marginal vein surrounds the entire wing edge, and the axillary valve is large. The feet are strong, the tibia is sometimes flat and wide, the middle tibia has two spurs, and the rear tibia sometimes lacks spurs, and has claw pads and interclaw processes. The abdomen is broad and hairy, flat, with 7 segments, and the copulatory apparatus is concealed. The eggs are long and needle-shaped, laid in clumps and covered with colloid. They are easily parasitized by black-egg wasps and are often mistaken for worm egg masses.

Larvae are rarely terrestrial, usually aquatic or semi-aquatic, spindle-shaped. Except for a small head, verse 11. Each segment has a raised ring to facilitate movement and a breathing tube at the end. Carnivorous, preying on small animals.

Adults are active during the day, with peak activity at noon. Good at flying. Commonly found near pools and water, flying quickly. Sometimes they suck nectar, but most commonly they are blood-loving. Female flies have strong stinging ability, and pachyderms such as cattle and horses are also susceptible to attacks. Female flies can fill their abdomens with blood within a few minutes each time. Warm-blooded animals, including humans, are affected. In the northeastern forest area, it can sometimes attack the exposed part of the neck very quickly, peck out large pieces of flesh and then escape. It is reported that the blood loss of a small horsefly bite can be up to 40 milligrams in one bite, and the largest horse flies, such as some species of the genus Glypsus and Oncodactylus, can cause the animal to lose 200 milligrams of blood in one bite. It has been recorded that a domestic animal can lose 100 ml of blood in one summer. Not only that, some horseflies can also spread anthrax to cattle, sheep and other livestock. Trypanosomiasis in camels in northwest my country and cattle and horses in southern China is caused by protozoa transmitted by horse flies. Horseflies can also spread anaplasmosis, tularensis fever, etc. Therefore, horseflies are important livestock pests.

Northwest is one of the main pastoral areas in my country. It is initially reported that there are 32 species of horseflies in this area (Deng Guofan, 1959). There are a total of 18 species of horseflies in Beijing and its adjacent areas.

Undergraduate studies have long reported that there are 2,500 known species (Essig, 1942), and now about 3,500 species are known, belonging to more than 200 genera. Nearly 200 species have been recorded in my country (1976).

animal tags： Gizzardidae Insecta Diptera Gadfly Niuhong