Dixa ubiquita

Moulton, John K., 2017, The true identity of Dixa modesta Johannsen (Diptera: Dixidae) resolved: synonymy of Dixa similis Johannsen, designation of the Dixa ubiquita species group, and description of three new eastern Nearctic species, Zootaxa 4216 (3), pp. 247-260 : 258

Key to males of Dixa ubiquita group.

1 Apex of basal gonocoxal lobe digitiform, equal in width to gonostylus ( Figs 18, 19, 20 ), with posterior margin noticeably concave in terminal view ( Fig. 20 ). Subepandrial sclerite with proximal lobe broad, rounded ventrally and distal lobe narrow, liplike in lateral view ( Fig. 18 ). Apex of gonostylus straight, not twisted medially ( Fig. 19 ). Northeastern Nearctic south to Appalachian Highlands of NC............................................................. D. vockerothi sp. nov.

- Apex of basal gonocoxal lobe more broadly rounded to squared, wider than gonostylus ( Figs 11 , 12, 15 ), with posterior margin straight or slightly concave in terminal view ( Figs 14, 17 ). Subepandrial sclerite with proximal lobe narrow, acute ventrally and distal lobe broad, rounded in lateral view ( Figs 11 , 12, 15 ). Apex of gonostylus twisted medially ( Figs 13, 16 ).......... 2

2 Apex of basal gonocoxal lobe in lateral view squared, 1/ 2X as wide as gonocoxal depth at mid-length ( Figs 11 , 12 ). Widespread.............................................................................. D. ubiquita sp. nov.

- Apex of basal gonocoxal lobe in lateral view more rounded, 1/3 or less times as wide as median gonocoxal depth ( Fig. 15 ). Currently known only from Little River (East Prong) in the Elkmont area of Great Smoky Mountains NP................................................................................................. D. elkmontensis sp. nov.

Figures

FIGURE 11. Dixa ubiquita sp. nov., male terminalia (rotated orientation), lateral view, with important structures labeled. Scale bar 50 µm

FIGURES 12 – 20. Male terminalia (rotated orientation), 12, Dixa ubiquita sp. nov., lateral view; 13, D. ubiquita sp. nov., ventral view; 14, D. ubiquita sp. nov., terminal view; 15, D. elkmontensis sp. nov., lateral view; 16, D. elkmontensis sp. nov., ventral view; 17, D. elkmontensis sp. nov., terminal view; 18, D. vockerothi, lateral view; 19, D. vockerothi, ventral view; 20, D. vockerothi, terminal view. Scale bar = 50 µm.