Sigmatineurum Parent

Evenhuis, Neal L., 2005, A review of the genera comprising species of the genus Eurynogaster sensu Hardy & Kohn, 1964 in Hawai‘i (Diptera: Dolichopodidae), Zootaxa 1017, pp. 39-60 : 53-55

Genus Sigmatineurum Parent

( Figs. 1, 9, 18, 26)

Sigmatineurum Parent, 1935: 215 . Type species: Sigmatineurum chalybeum Parent, 1935 , by original designation.

Evenhuis & Polhemus (1994) and Evenhuis (1997) reviewed the genus and provided characters to distinguish Sigmatineurum from related genera in Hawai‘i. Subsequent discoveries of additional species ( Evenhuis 2000; Englund & Evenhuis 2005) has led to a refined definition of the genus.

Diagnosis: Most similar to Elmoia in both genera having the fourth abdominal sternite possessing a posteromedial ventral process, but can be separated from it by the hypopygium with a clavate apex of the basoventral epandrial lobe (this lobe not clavate in Elmoia ) and the CuAx ratio> 2.5 (closer to 1 in Elmoia ).

Hypopygium ( Fig. 26): Cercus rounded, hemispherical, with small process apicodorsally; surstylus unilobed, with hairs and modified setae at apex; basiventral epandrial lobe long, thin, sinuous, with clavate or swollen apex; apicoventral epandrial lobe inserted basad of surstylus long, thin, with short apical hairs; hypandrium broad, bladelike, with slightly recurved hook­like apex.

Discussion: A re­examination of the hypopygium in this study shows that what appears to be a bilobed surstylus is actually a unilobed surstylus and an apicoventral epan­ drial lobe in close approximation to the surstylus as is evidenced from internal skeletal structures of the hypopygium. A similar condition is found in Uropachys .

Included Species: Sigmatineurum binodatum (Parent) , S. chalybeum Parent , S. englundi Evenhuis *, S. iao Evenhuis *, S. meaohi Evenhuis *, S. mnemogagne Evenhuis *, S. napali Evenhuis *, S. nigrum Evenhuis *, S. omega Evenhuis *, S. parenti Evenhuis *, S. puleloai Englund & Evenhuis *.