Ochterus thienemanni Jaczewski, 1935

Polhemus, Dan A. & Polhemus, John T., 2012, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. Ix. Infraorder Nepomorpha, Families Ochteridae And Gelastocoridae, Raffles Bulletin of Zoology 60 (2), pp. 343-359 : 353-354

Ochterus thienemanni Jaczewski

( Figs. 21 , 23–25 , 30 )

Ochterus thienemanni Jaczewski, 1935: 480

Material examined. — INDONESIA, Bengkulu Prov.: 1 male, Sumatra, Ketelang River , 39 km. SE of Muaraaman, 720 m ., 3°19'48"S, 102°26'32"E, water temp. 21.5°C., 8 Sep.1991, CL 2585, D. A. & J. T . Polhemus ( JTPC) . Jawa Barat Prov.: 1 male, 1 female, Java, Preanger N. O. I., Bandoeng [Priangan district, N. of Bandung], 750 m ., 19 Apr.1936, FCD 29, coll. F. C. Drescher, det. Ochterus thienemanni by N. Kormilev, 1973 ( JTPC) ; 2 females, Kabupaten Cianjur, small stream on Gede trail, Gede-Pangrango National Park , above Cibodas , 1350 m., 3 Nov.1985, CL 2185, coll. D. A. & J. T . Polhemus ( JTPC) ; 1 female, Kabupaten Cianjur, swift rocky stream at Cibodas , 1300 m., 3 Nov.1985, CL 2186, coll. D. A. & J. T . Polhemus ( JTPC) . Bali Prov.: 2 males, 1 female, Bali, Kabupaten Bangli, Melangit River , 400 m, 17 Oct.1985, CL 2170, coll. D. A. & J. T . Polhemus ( JTPC) .

Diagnosis. — Male body length 4.50, maximum width (across hemelytra) 2.50; female body length 4.90, maximum width (across hemelytra) 2.85. Colouration dark brown to black, flecked with pale blue markings on the hemelytra; posterior margin of pronotum narrowly dark yellow, this colouration from Sumatra (Panjingahan Waterfall, near Singkarak), and the original description also recorded this species from the adjacent Greater Sunda Islands of Java and Bali ( Jaczewski, 1935). The misinterpretation of this species by Kormilev (1971), and subsequently Baehr (1990b), has greatly hindered its proper recognition in more recent decades. While preparing his work on the Ochteridae of the Australasian region, Kormilev (1971) did not examine any specimens from the Greater Sunda Islands, but instead based his redescription on two specimens from Papua New Guinea. In this he was followed by Baehr (1990b), who re-examined one of the two New Guinea specimens used by Kormilev, noting that the holotype of O. thienemanni had been in the Warszava [Warsaw] Museum, but might have been lost during World War II (Jaczewski, in a personal communication to the second author, also noted that most of his collection had been destroyed in the war, thus supporting the suggestion that the holotype may be lost). In spite of this, the figure of the male right paramere provided by Jaczewski (1935), though small in scale, shows sufficient distinctive structural details, particularly of the dentation on the inner margin of the superior appendage, to permit unequivocal identification within the regional suite of Greater Sunda Island Ochterus species.

Diagnosis. — Male body length 3.95–3.98, maximum width (across hemelytra) 2.20–2.28; female body length 4.10–4.20, maximum width (across hemelytra) 2.45–2.50. Colouration reddish brown, flecked with small lavendar patches, head and scutellum black ( Fig. 22 ). Head with frons bearing coarse striations, these striations becoming obscure on clypeus, inner margins of eyes bordered by narrow channels, these channels lacking transverse striations ( Fig. 33 ). Male genitalia with right paramere bearing appendages of unequal size, inferior appendate with apex multidentate, superior appendage with We have now re-examined one of the New Guinea specimens in the Bishop Museum determined as O. thienemanni by Kormilev, and subsequently Baehr, and found that it does not represent O. thienemanni , but rather a superficially similar Papuan species. This is not surprising, given the overwhelmingly insular and endemic nature of the New Guinea ochterid biota. By contrast, new material is now at hand from the Greater Sunda Islands that completely matches the original description of O. thienemanni by Jaczewski. This material includes several specimens determined as this species by Kormilev in 1973, subsequent to the publication of his 1971 revision. A redescription and re-illustration has been provided herein based on these more recent specimens.

Ecological notes. — On the basis of the original collection locality data provided in Jaczewski (1935), as well as the subsequent sites from which this species has been collected, O. thienemanni appears to prefer vertical rheocrenes or wet rocks along upland streams in hill forests, in contrast to O. marginatus which is found on littoral habitats such as sand or mud bars along the marigns of reserviors or slow streams in the lowlands.

Figures

Figs. 21–22. Ochterus species, colour photographs of dorsum. 21, O. thienemanni Jaczewski, specimen from Indonesia, Bali, CL 2170. 22, O. noualhieri Baehr, specimen from Indonesia, Celebes, CL 2127.

Figs. 23–25. O. thienemanni Jaczewski, male, structural details, specimen from Indonesia, Bali, CL 2170. 23, Male right paramere. 24, Superior appendage of right paramere. 25, Medial process of pygophore.

Figs. 29–34. Ochterus species, colour photographs of head, anterior view, showing pattern of striations on frons.29, O. marginatus (Latreille), female, specimen from Vietnam, Cao Bang Prov., CL 4368. 30, O. thienemanni Jaczewski, female, specimen from Indonesia, Bali Prov., CL 2170. 31, O. signatus, new species, female, specimen from Vietnam, Lam Dong Prov., CL3085. 32, O. pseudomarginatus, new species, female, specimen from Malaysia, Perak, CL 2078. 33, O. noualhieri Baehr, female, specimen from Indonesia, Sulawesi Utara Prov., CL 2114. 34, O. singaporensis, new species, male, specimen from Singapore, Bukit Timah.