Neriidae, Westwood, 1840

Sepúlveda, Tatiana A., Echeverry, Angela & Souza, Diego De S., 2020, New species of Chaetonerius Hendel (Diptera: Neriidae) and key for identification of the Neriidae of Tanzania, Zootaxa 4755 (1), pp. 190-194 : 192

Key for identification of the Neriidae of Tanzania

1 Arista white and densely pubescent at base and brown with more scattered pubescence on distal half. Ventral half of occiput brown with median yellow stripe near posterior margin of eye. Fore coxa without anterolateral seta; if one seta present, thin and short. Femora yellow or pale brown with dark apex. Male ( Barraclough 1993b): surstylus bilobed, upper lobe very slender, medioventrally directed such that apex is concealed by lower lobe in profile, lower lobe broad and thumb-like; upper lobe slightly shorter than lower lobe, which is slightly shorter than cercus........................ Chaetonerius apicalis (Walker)

1’ Arista entirely brown with pubescence homogeneously sparse in all its extension. Ventral half of occiput entirely brown ( Fig. 1C ). Fore coxa with at least one well-developed anterolateral seta. Femora brown or pale brown with yellow ring on distal third; sometimes, fore femur homogeneously colored ( Fig. 1D ). Male ( Barraclough 1993b): surstylus with one only lobe, noticeably broader apically (spoon-shaped) in profile; unusually elongate, almost as long to slightly longer than cercus............. 2

2 Posterior fronto-orbital seta only slightly lateroclinate to straight. Male (Barraclough 1993): cercus linear, much broader apically, at least 2.0−3.0X basal width and apical margin very broadly rounded; near same length as surstylus; bearing long and thin setae dorsally and ventrally.............................................. Chaetonerius perstriatus (Speiser)

2’ Posterior fronto-orbital seta patently lateroclinate and inner vertical seta inclinate. Male: cercus rectangular, with apical width only slightly larger than base and apically truncate ( Fig. 1G ); cercus shorter than surstylus, with ventral setae short and thick, densely positioned towards distal margin, and dorsal setae long, thin and scattered.... Chaetonerius stichodactylus sp. nov.

Figures

FIGURE 1. Chaetonerius stichodactylus sp. n., holotype male: A, head frontal; B, head lateroventral; C, head laterodorsal; D, habitus lateral; E, habitus dorsal; F, wing; G, genitalia ventral. Abbreviations: a f-orb s, anterior fronto-orbital seta; ar, arista; cerc, cercus; distph, distiphallus; epand, epandrium; hypd, hypandrium; i vt s, inner vertical seta; m f-orb s, mid fronto-orbital seta; o vt s, outer vertical seta; p f-orb s, posterior fronto-orbital seta; poc s, postocellar seta; sur, surstylus.