Pherbellia ditoma STEYSKAL, 1956

Rozkošný, R., Knutson, L. & Merz, B., 2010, A Review Of The Korean Sciomyzidae (Diptera) With Taxonomic And Distributional Notes, Acta Zoologica Academiae Scientiarum Hungaricae 56 (4), pp. 371-382 : 373-374

Pherbellia ditoma STEYSKAL, 1956

This species differs from other Palaearctic Pherbellia species by a conspicuous apomorphic character – two (rarely three) stump veins below on the distal section of M 1+2 and by the species-specific male terminalia (see STEYSKAL 1956). Other important characters are: midfrontal stripe short; orbito-antennal spot very light brownish; fore basitarsus white except extreme apex, strongly contrasting with distal four blackish tarsomeres; anepisternum bare; anepimeron with a group of 3 or 4 strong setae.

The specimens that we examined agree well with STEYSKAL’ s (1956) description except in our specimens all femora and tibiae are yellowish suffused with grey (not “blackish”), the fore femur and tibia darkest. Also, the female from Minjujisan has a medially slightly incomplete posterior crossvein (in both wings) in the cell above the last stump vein on vein M 1+2. The pin obliterated the prescutellar dorsocentral area of the scutum in STEYSKAL’s specimens including the holotype. SUEYOSHI (2001) noted two acrostichal setae but all of our specimens have only one pair of prescutellar acrostichals. STEYSKAL (1956) described the wing as “hyaline, with brownish clouding on the crossveins and the two stump veins”. In our specimens, the anterior margin of the wing, as well as crossveins, are distinctly infumated greyish.

In STEYSKAL’ s description, reference to the anterior and posterior surstyli is inverted; it is the anterior surstylus that has a strong preapical tooth on the posterior margin.

Distribution: South Korea: Andong ( STEYSKAL 1956) and material examined; Japan ( SUEYOSHI 2001, 2010).

Material examined: South Korea: Minjujisan, between Kimeh’on and Yangdang, 15.x.1997, with net above stream, 1 m, 1 f; Posok-sa (Keumsan), 10.–14.ix.1998, 1 f, in MNHNP; same locality, 18.–21.ix. 1928, 1 m; 19.–21.ix.1928, 1 f, in USNM; all Malaise trap, all P. TRIPOTIN leg. and L. KNUTSON det .