This species and the similar T. geminatus are the most commonly encountered flower flies (family Syrphidae) in Maryland. T. marginatus has been recorded from every county and occurs in a wide variety of habitats, including fields, forests, and disturbed habitats. It is the smallest of the yellow-and-black flower flies regularly found in Maryland, with a reported size range of 4.9-5.7 mm (Skevington, 2019). Adults visit a variety of flowers. Larvae are carnivorous and feed on aphids, small caterpillars, and other small, soft-bodied insects.
T. marginatus can be identified from photos with care. The species is variable in appearance and adults can be darker if the pupae are exposed to cold (BugGuide). One key feature is the presence of an entirely yellow abdominal margin (the margin visible from the side), with none of the black striping extending to the margin, as is typical of T. geminatus. Another member of the genus common in Maryland, T. politus, is larger and has iridescent dark blue rather than black striping, among other differences.
There are 573 records in the project database.
| GA | AL | WA | FR | CL | MO | HO | BA | BC | HA | CE | PG | AA | CV | CH | SM | KE | QA | CN | TA | DO | WI | SO | WO |
