Taxonomic Accounts of Horse Flies (Insecta: Diptera: Tabanidae) of West Bengal: Occasional Paper No. 381

Contents: 1. Introduction. 2. Material and methods. 3. Systematic list. 4. Systematic account. 5. Discussion. 6. Summary. 7. Acknowledgements. 8. References.

From the introduction: Flies of family Tabanidae are true Brachyceran flies under infraorder Tabanomorpha and superfamily Tabanoidea. They are commonly known as “Dansmachi” in India. They are true flies with varying sizes, commonly known as deerfly, horsefly and clegs for their disease causing vector capabilities in different wild animals like horses, deer, cattle and other livestock. They are mainly large bodied sturdy flies and their size ranges from 7-33 mm, known for their furious bite to vertebrate animals including human. Flies of this family are mainly characterised on the basis of sickle shaped antennae (3rd segment annulated), pulvilliform empodium, and 4th and 5th radial veins which always terminate on either side of the wing (Thomas, 2011). Males and females of this family are mainly differentiated in terms of eyes, being separated in females and contiguous in males. They are generally with broad bodies and bulging eyes. The adults of both sexes feed on nectar and pollen of flowers and also known to take blood meals from vertebrate animals mainly during their reproductive period (Chainey, 2014).

Tabanids have a wide range of habitats and some of them even prefer bushy regions. They are found in large numbers in agricultural fields, to be closely associated with domestic cattle, kept for feeding throughout the day specially during rainy season, when sunlight comes out after rain and during their return from the field after sunset respectively. Immature stages of tabanids are often found in damp environments, such as wetland or bushy regions near streams. Some horseflies are seen to fly on lighted streets, stroking on window glasses in night or entering lighted house (Datta, 1991).