Tabanus autumnalis a beastly fly

 

In September 2019 I found an absolute beast of a horse fly, which I have since recorded in my kitchen this year which gave me a bit of a jump before I shooed it out. I am in the process of sorting through a while bunch of insect photos from the past few years, so it would be rude not to revisit some (probably wont get much sorting done). This particular fly sticks in the memory, not least due to its large formidable size but at that point in time it was the most northerly Yorkshire record, at the northern edge of VC61. 

T. autumnalis more affectionately known as the Large Marsh Horsefly has been slowly spreading north through Yorkshire in association with wetland sites and is well established at places like North Cave Wetlands. Typically a species which is more scarce than congeners T. bromius and T. bovinus, with more of a preference for coastal areas particularly coastal grazing marsh and upper salt marsh. This species tolerates relatively brackish conditions although typicallly freshwater seepages are sought in such circumstances for breeding. 

In general a species associated with cattle on grazing marshes, where its basic ecology consists of the adult (female) feeding on cows blood and breeding within the marsh where larval development occurs, in wet mud and detritus in pool and ditch bases, with larva being predatory. As with other horsefly species the adult males do not bite but instead feed on nectar and plant sap, females basically require proteins within blood for egg development.