Rhopalopsole alobata, sp.n.

(Figs. 1‐5)

Material examined. Holotype ♂ from Vietnam, Vinh Phu, Tam Dao Hill Station, lower waterfall of stream flowing through town, UV light, 11 May 1996, B. Hubley, D.C. Darling, ROM 961030. Holotype deposited in the ROM .

Adult habitus. Head brown, lighter toward margins. Large, longitudinal, dark brown pattern extending from occiput through ocelli to anterior frons and labrum. Area forward of compound eye and anterolateral to posterior ocelli pale. Wing membrane pale brown, veins lighter except R vein dark brown. Legs pale brown without distinctive pattern.

Male. Macropterous, Forewing length 5.5 mm. Vesicle absent (Figs. 2‐3). Posterior margin of tergum 9 sclerotized, slightly lobed and emarginate (Fig. 1). Tergum 10 with mesal sclerotized plate bearing a rounded posteromedian protrusion and lateral wings. Posterolateral processes strongly sclerotized, finger‐ like in shape, curving inward at tip in dorsal aspect (Fig 1), broad basally, narrowed to tip and curved upward in lateral aspect (Fig. 3). Subanal probe sinuate in lateral aspect with hook‐ like tip (Figs. 3, 5), base of probe strongly sclerotized in ventral aspect (Fig. 2), and apex membranous. Epiproct a simple curved process (Figs. 3‐4), obscured in Fig. 1 by position of subanal probe.

Female. Unknown.

Larva. Unknown.

Etymology. The species name refers to the absence of a ventral vesicle on segment 9.

Diagnosis. This species is similar to R. xui Yang, et al. (2004), but lacks a vesicle on the base of sternum 9. R. alobata and R. xui are similar in that the lateral processes of tergum 10 are simple finger‐ like, non bifurcate structures, but differ in that these structures in R. alobata curve inward at the tip in dorsal aspect and also curve more dorsad than in R. xui in lateral aspect.