Chetoneura, Colless, 1962

Kazandzhieva, Svetlozara & Bechev, Dimitar, 2022, A new species of Chetoneura Colless from Borneo (Diptera: Keroplatidae), Zootaxa 5104 (4), pp. 593-599 : 597-598

Key to the species of Chetoneura

1. R-M fusion very short ( Fig. 2 ). Tergite IX slightly longer than broad or up to about 1.7 as long as wide, not subtriangular... 2

- R-M fusion as long as r-m or more. Tergite IX shorter than broad, subtriangular.................................... 4

2. Scutum yellowish, with lateral margins and two submedian longitudinal stripes dark. Tergite IX slightly longer than broad, length/width ratio about 1/1. Form of tergite IX— Fig. 7 ........................ Ch. davidi Ševčík, Hippa & Burdiková

- Scutum light yellowish brown, without bands or brown, with thin darker brown oblique bands. Tergite IX apparently longer than broad, length/width ratio about 4/3 or more............................................................. 3

3. Tergite IX length/width ratio about 4/3. Form of tergite IX— Fig. 8 . Gonostylus stout, with a thorn-like apical spine ( Colless 1962: Fig. 1c )........................................................................ Ch. cavernae Colless

- Tergite IX length/width ratio about 5/3. Form of tergite IX— Fig. 9 . Gonostylus not stout, elongated in ventral view, with elongated sharp apical spine ( Figs 5–6 )................................. Ch. lagangensis, Kazandzhieva & Bechev , sp. n.

4. Fore tibia without apical spur......................................................... Ch. oligoradiata (Papp)

- Fore tibia with very short apical spur....................................... Ch. shennonggongensis Amorim & Niu

Figures

FIGURE 1. Chetoneura lagangеnsis sp. n., habitus, lateral view.

FIGURE 2. Chetoneura lagangеnsis sp. n., wing, view from below.

FIGURES 7–9. Form of tergite IX (not in scale): 7—Ch. davidi (by Ševčík et al. 2021: Fig. 13C); 8—Ch. cavernae (by Colless 1962: Fig. 1c); 9—Ch. lagangеnsis sp. n.

FIGURES 3–6. Chetoneura lagangеnsis sp. n., male terminalia: 3—dorsal view, 4—lateral view; 5—ventral view; 6—posterior view. Abbreviation: aps = apical spine of gonostylus; cer = cerci; gcx = gonocoxite; gst = gonostylus; hyp = hypoproct; T9 = tergite IX.