Thoracic setae
The number and position of the setae on the thorax of Calliphorids (at least in North America) are critical for the determination of species. I made this figure to help me identify local Calliphorids and thought that it may be useful to others.
The setae are named based on their position and location, anterior-to or posterior-to the transverse suture (4). The setae are similar (repeated) either side of the mid-line.
- 1 acrostichal setae; presutural (2 in this fly) and postsutural (3 in this fly)
- 2 dorsocentral setae; presutural (3 in this fly) and postsutural (3 in this fly)
- 3 intra-alar setae; presutural (1 in this fly just above transverse suture) and postsutural (2 in this fly)
- 4 transverse suture
- 5 scutellum

Less important for species identification are:
- 6 presutural seta
- 7 posthumeral setae
- 8 humeral lobe with humeral setae