Hydrellia, Robineau-Desvoidy, 1830

Dawah, Hassan A., Ahmad, Syed K., Abdullah, Mohammed A. & Zatwarnicki, Tadeusz, 2019, An overview of the Ephydridae (Diptera) of Saudi Arabia, Zootaxa 4711 (3), pp. 401-445 : 415

Key to species of Hydrellia from the Saudi Arabia

1. Mesonotum only slightly darker than pleural areas, greenish to tannish gray generally, lacking a contrasted, lateral, mesonotal stripe; anepisternum uniformly unicolorous................................................................. 2

- Mesonotum with broad medial portion mostly brown, contrasted distinctly with lateral mesonotal, grayish stripe from postpronotum through notopleuron; anepisternum golden tan dorsally, gradually becoming grayer ventrally................................................................................................... H. latipalpis Cresson, 1943

2. Anterior fronto-orbital seta in front of anterior ocellus; lunula yellowish; antenna with four aristal rays; presutural dorsocentral seta lacking...................................................................... H. griseola ( Fallén, 1813)

- Anterior fronto-orbital seta behind of anterior ocellus; lunula whitish; antenna with five aristal rays; presutural dorsocentral seta present............................................................................ H. maura Meigen, 1838