7.5-12mm. A relatively large tachinid. Males have strong orange sides to the abdomen with a broad, dark medial stripe - about one third the width of the abdomen. Both sexes have 4 strong bristles on the mid tibia (only 2-3 in T. nigrina). Females lack the orange sides.

Thelaira nigrina has less orange on the male abdomen and only 2-3 strong bristles on the mid tibia.

• 7.5-12mm
• males have strong orange sides
• 4 strong bristles on the mid tibia
• calypters and wing bases have a yellow-orange tinge

Uncommon though widespread in England up to the midlands.

Rare.