Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. Ix. Infraorder Nepomorpha, Families Ochteridae And Gelastocoridae Author Polhemus, Dan A. Author Polhemus, John T. text Raffles Bulletin of Zoology 2012 2012-08-31 60 2 343 359 journal article 10.5281/zenodo.5348151 2345-7600 5348151 KEY TO SPECIES OF OCHTERUS occurring in Singapore , Peninsular Malaysia , Sumatra, and Java 1. Hemelytral margins bearing 2–3 yellowish patches on each side ( Figs. 1, 4 ) ............................................................................. 2 – Hemelytral margins without yellowish patches, instead bearing at least 3 bluish to lavendar patches on each side ( Figs. 2, 3 , 21, 22 ) .................................................................................... 3 2. Appendages of male right paramere short, lacking asperities, with apices angulate ( Figs. 17, 18 ); posterior margin of pronotum narrowly margined with dark yellow, but lacking a yellowish patch posteromedially ( Fig. 4 ); frons and clypeus with only a few weak striations ( Fig. 34 ); small species, length of males less than 4.0 mm, length of females less than 5.0 mm; .................................................. O . singaporensis new species – Appendages of male right paramere elongate, unequal in size, apices bidentate, larger of these appendages bearing small asperities ( Figs. 5, 7 ); posterior margin of pronotum bearing a yellowish patch posteromedially ( Fig. 1 ); entire frons and clypeus densely striate ( Fig. 29 ); larger species than above, length of males greater than 4.0 mm, length of females greater than 4.5 mm .................................... O . marginatus (Latreille) 3. Large species, body length in both sexes equal to or exceeding 5.0 mm; inner section of corium bearing a large, prominent orange-brown patch ( Fig. 2 ); frons bearing broad, transversely striate channels parallel to inner eye margins ( Fig. 31 ); male right paramere with both appendages large, boot-shaped ( Fig. 10, 11 ) ............................................... O . signatus new species – Moderate sized to small sized species, body length in both sexes less than 5.0 mm; inner section of corium lacking a prominent orange-brown patch, ground color instead brown to black, flecked with bluish or lavendar markings ( Figs. 3 , 21, 22 ); frons bearing narrow channels parallel to inner eye margins, these channels lacking transverse striations except for a few at extreme anterior extremities ( Figs. 30, 32, 33 ); male right paramere with appendages smaller, frequently unequal in size, not boot-shaped ( Figs. 13, 14 , 23, 24 , 26, 27 ) ..................... 4 4. Length in both sexes less than 4.5 mm ; ground colouration brown to orange-brown, flecked with lavendar patches ( Fig. 22 ); lavendar flecks on wing membrane confined to posterior half ( Fig. 22 ); superior appendage of male right paramere with a deep concavity at apex ( Figs. 26, 27 ) ... O . noualhieri Baehr – Length in both sexes greater than or equal to 4.5 mm ; ground colouration black, flecked with bluish or lavendar patches ( Figs. 3 , 21 ); lavendar flecks present on entire wing membrane, not confined to posterior half ( Figs. 3 , 21 ); superior appendage on male right paramere lacking a deep concavity at apex ( Figs. 13, 14 , 23, 24 ) ....................................................................... 5 5. Pronotum with a yellowish patch posteromedially ( Fig. 3 ); appendices of male right paramere subequal in size, inner margins lacking teeth ( Figs. 13, 14 ) ........................................ .......................................... O . pseudomarginatus new species – Pronotum lacking a yellowish patch posteromedially ( Fig. 22 ); appendices of male right paramere markedly unequal in size, inner margin of larger appendage with several small teeth ( Fig. 23, 24 ) ........................................... O . thienemanni Jaczewski