Ochterus marginatus marginatus (Latreille)

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 : 345-347

Ochterus marginatus marginatus (Latreille)

( Figs. 1 , 5–9 , 29 )

Acanthia marginata Latreille, 1804: 242

Ochterus marginatus: Latreille, 1807: 143

Ochterus marginatus marginatus: Jaczewski, 1934: 602

Ochterus marginatus insularis: Rieger, 1977: 213

Material examined. — SINGAPORE: 2 males, 3 females, Selatar Reservoir park, 3 Jan.1991, coll. K. L. Yeo, YKL0723 ( ZRC) ; 2 males, 1 female, same data as previous, except 7 Nov.1990, coll. K. L. Yeo, YKL705 ( ZRC) ; 1 male (head and thorax missing), Nee Soon Swamp Forest , outflow creek, on sand banks, 1 Jan.1986, coll. D. H. Murphy ( ZRC) ; 1 male, Bukit Panjang , wet sandy area in bright sun, 19 Jan.1976, coll. D. H. Murphy ( ZRC) . MALAYSIA, Terengganu: 1 female, Rantau Abang , 18 Mar.1992, coll. H. K. Lua, LHK 177 ( ZRC) . Selangor: 1 male, Kepong, FRIM, Sungai Kroh , 15 Jan.2002, coll. H. H. Tan ( ZRC) . Pahang: 1 male, 1 female, Selompok, pond, 12 Aug.1926, coll. C. Dover ( ZRC) ; 1 male, Cheroh River, 6 km. E. of Tapah , 18 Aug.1985, CL 2072, coll. D. A. and J. T. Polhemus ( JTPC) .

Extralimital material examined. — GREECE: 1 male, 1 female, Cyprus, Ayia Irini River , on banks under stones, 28 Nov.1947, coll. G. Mavromoustakis ( USNM) . ISRAEL: 3 males, ‘ Enot Zuqim (‘ EnFashka) shore, Dead Sea , 23 Aug.1990, coll. W. N. Mathis ( USNM) . TANZANIA: 1 male, Ilonga , 11 Feb.1963, light trap, coll. I. A. D. Robertson ( USNM) . INDIA, Tamil Nadu: 1 male, South India, Coimbatore , Jan.1956, coll. P. Susai Nathan (det. as O. marginatus by N. Kormilev, 1974, USNM) . Assam: 1 male, 3 females, 10 mi. N. of Tinsukia , 5 Apr.1944, coll. G. F. Johnstone ( USNM) . West Bengal: 2 males, 3 females, Calcutta [Kolkata], 1 Aug.1944, coll. D. E. Haredy ( USNM) . SRI LANKA, Uva Prov.: 4 males, 4 females, Badulla, Dist., 5 mi. E. of Mahiyangana , 1 Apr.1971, coll. P. & P. Spangler ( USNM) . THAILAND, Khon Kaen Prov.: Ban Nam Pong , T 92 , 10 Mar.1971, coll. P. & P. Spangler ( USNM) . VIETNAM, Cao Bang Prov.: 2 males, 2 females, Ba Be National Park, south end of Ba Be Lake at river inflow, 170 m ., 21 Mar.2000, CL 4368, coll. J. T. Polhemus & P. Nguyen ( JTPC) . INDONESIA, Bali Prov.: 3 males, Bali, Kabupaten Bangli, Melangit River , 400 m ., 17 Oct.1985, CL 2170, coll. D. A. & J. T. Polhemus ( JTPC) .

Diagnosis. — Male body length 4.10–4.60, maximum width (across hemelytra) 2.40–2.60; female body length 4.75–4.80, maximum width (across hemelytra) 2.60–2.62. Colouration reddish brown, with each hemelytral margin bearing three prominent, evenly spaced, dark yellow spots ( Fig. 1 ). Frons and clypeus densely striate ( Fig. 29 ). Male genitalia with male right paramere bearing appendages of unequal width ( Figs. 5–7 ), process of pygophore with medial process prominent, posterior margin weakly sinuate ( Figs. 8, 9 ).

Distribution. — Widespread in the Eastern Hemisphere, from the Mediterranean south into Africa, and eastward to India, Ceylon, China, Japan, Taiwan, Thailand, Laos, Vietnam, Malaysia, the Philippines (Luzon, Mindanao), Sumatra, Java, Bali, Borneo, and Sulawesi. This species has not been recorded from New Guinea or Australia, despite extensive collecting for Ochterus in those areas, and apparently does not occur there.

Discussion. — This species is widespread in the lowlands of Southeast Asia, and exhibits a degree of intraspecific

morphological variation across this range, but can be recognised by the very slender inferior appendage on the male right paramere. The male genitalia of specimens from Singapore and Malaysia are structurally similar to those from India, and other extralimital areas to the west (see Extralimital Material Examined for populations used in this comparison). Moving eastward into the Malay Archipelago, specimens from Bali are smaller than those from continental Southeast Asia, with lengths of 4.20–4.25, widths of 2.20–2.25, have slightly different shapes of the superior appendage on the male right paramere (compare Figs. 6, 7 ), and a somewhat differently shaped process of the male pygophore (compare Figs. 8, 9 ). These more eastern populations may be assignable to the subspecies O. marginatus insularis , originally described by Rieger (1977) from Mindanao, but an analysis of further material from throughout the Malay Archipelago region is necessary to properly determine the subspecific designations that should be applied to these insular forms.

Rieger (1976) provided a detailed study of the exoskeletal morphology and musculature of this species.

Ecological notes. — Occurs on open, sandy or muddy substrates along the margins of lowland streams or rice paddies. Many specimens in major collections have label data indicating that they were taken at light traps.

Figures

Figs. 1–4. Ochterus species, colour photographs of dorsum. 1, O. marginatus (Latreille), specimen from Thailand, Chonburi Prov. 2, O. signatus, new species, specimen from Malaysia, Perak, CL 2081. 3, O. pseudomarginatus, new species, specimen from Malaysia, Pahang, CL 2072. 4, O. singaporensis, new species, specimen from Singapore, Bukit Timah.

Figs. 5–9. O. marginatus (Latreille), male, structural details. 5, Male right paramere, specimen from Vietnam, CL 4368.6, Superior appendage of right paramere, specimen from Vietnam, CL 4368. 7, Superior appendage of right paramere, specimen from Indonesia, Bali, CL 2170. 8, Medial process of pygophore, specimen from Vietnam, CL 4368. 9, Medial process of pygophore, specimen from Indonesia, Bali, CL 2170.

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.