Ranatra thai Lansbury, 1972

Polhemus, Dan A. & Polhemus, John T., 2013, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. X. Infraorder Nepomorpha-Famlies Belostomatidae And Nepidae, Raffles Bulletin of Zoology 61 (1), pp. 25-45 : 36-38

publication ID

https://doi.org/ 10.5281/zenodo.5351508

persistent identifier

https://treatment.plazi.org/id/03C6879C-103B-7313-FC30-FC84DD30AFDF

treatment provided by

Tatiana

scientific name

Ranatra thai Lansbury, 1972
status

 

Ranatra thai Lansbury, 1972 View in CoL

( Figs. 10 View Figs , 21, 22 View Figs )

Ranatra longipes thai Lansbury, 1972: 334 View in CoL

Ranatra thai: Tran & D. Polhemus, 2012: 102 View in CoL

Material examined. — The following additional records are in addition to those listed in Tran & Polhemus (2012): MALAYSIA, Johor: 2 males, 3 males, Pontian, stream along road to Pekan Nanas, 15 Aug.1995, coll. H. K. Lua ( ZRC) ; 2 males, 1 female, Layang Layang stream 1, muddy water with vegetation on side, 6 Feb.1991, coll. NUS staff ( ZRC) . Perak: 1 male, near Sungai Bernam headwater works, 16 Jun. 19919, coll. H. K. Lua, LHK160 ( ZRC) .

Diagnosis. — Male body length 21–24 mm, length of respiratory siphon 18–24 mm; female body length 22–27 mm, length of respiratory siphon 18–24 mm. Colouration including legs medium brown. Head with vertex raised centrally ( Fig. 10 View Figs ), sometimes with a small nodular tubercle in males. Ventral prothorax with a prominent medial longitudinal setiferous carina present along entire length. Fore femur long and slender, with two teeth distal of midpoint on the margin adjacent to the infolded tibia, consisting of a moderate sized tooth on outer face and a smaller tooth on inner face (similar to Fig. 27 View Figs ); middle and hind tibiae subequal in length, both longer than both middle and hind femora; hind femora in both sexes when folded back along body slightly exceeding apex of operculum. Male paramere with a moderately broad and deep incision subapically, isolating a distal hook that is only weakly expanded distally and not weakly toothed; subapical lobe absent ( Figs. 21, 22 View Figs ).

Distribution. — Originally described from Thailand ( Lansbury, 1972) and subsequently recorded from Langkawi Island in the Peninsular Malaysian state of Kedah (Zettel & Tran, 2009). Additional records for the Peninsular Malaysian states of Terengganu, Selangor, Pahang, Malacca, and Johor, as well as from further localities in Vietnam, and Thailand, were provided by Tran & D. Polhemus (2012), and we provide new records from the Malaysian states of of Johor and Perak herein.

Discussion. — Lansbury (1972) described the subspecies Ranatra longipes thai based on specimens from various localities in Thailand. Tran & D. Polhemus (2012), following a fine-scale analysis of male paramere structure, elevated Lansbury’s subspecies to full species status. This is the most widespread and commonly encountered Ranatra species in Peninsular Malaysia north of Johor, but definitive separation from R. longipes requires measurement of leg segment ratios, or a genitalic dissection. In R. thai the distal hook of the male paramere lacks a small subapical tooth (compare Figs. 19, 20 View Figs to 21, 22), and the middle and hind femora are subequal in length, rather than the hind femur being distinctly longer than the middle femur as in R. longipes .

ZRC

Zoological Reference Collection, National University of Singapore

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hemiptera

Family

Nepidae

Genus

Ranatra

Loc

Ranatra thai Lansbury, 1972

Polhemus, Dan A. & Polhemus, John T. 2013
2013
Loc

Ranatra longipes thai

Lansbury, I 1972: 334
1972
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