Ranatra filiformis, Fabricius, 1790

Tran, A. D. & Zettel, H., 2021, Taxonomic review of the Ranatra gracilis group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of four new species, Raffles Bulletin of Zoology 69, pp. 45-70 : 48

Ranatra filiformis group sensu Lansbury, 1972

Diagnosis. Smaller species, body length: males 22–27, females 24–30; siphon moderate to long, ratio of siphon length: body length around 0.7–0.9; vertex in lateral view higher than eye, evenly round, without or with very low tubercle; ratio of eye width: interocular width 0.65–0.98; ratio of anterior pronotal length: posterior pronotal length 1.3–1.7; fore femur slender, flexor side with two teeth nearer to distal end, larger one proximal to smaller one, pre-apical teeth absent; metasternum with posterior margin usually convex (sometimes straight or slightly emarginated); operculum of female at most reaching apex of connexivum.

Species included. Ranatra filiformis Fabricius, 1790 , R. diminuta Montandon, 1907 , R. occidentalis Lansbury, 1972 , and R. akoitachta Nieser, 1996 .

Note. For comparison between species of this group, see Lansbury (1972) and Nieser (1996).