Heleocoris ovatus Montandon, 1897

Polhemus, Dan A. & Polhemus, John T., 2013, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. Xi. Infraorder Nepomorpha- Families Naucoridae And Aphelocheiridae, Raffles Bulletin of Zoology 61 (2), pp. 665-686 : 678-679

Heleocoris ovatus Montandon, 1897

( Figs. 27 , 35 )

Heleocoris ovatus Montandon, 1897b: 451

Extralimital material examined. — VIETNAM, Nghê An Prov.: 6 males, 2 females, Pu Mat Nature Reserve, SW of Con Cuông, Khe Moi stream, 235 m, water temp. 22°C., 1 Apr.2000, CL 4382, coll. J. T . Polhemus & P. Nguyen ( JTPC, BPBM) . Lam Dong Prov.: 5 males, 3 females, Pongour Falls , 47 km SW of Dalat, 825 m, 11°41'19"N, 108°15'55"E, water temp. 25.5°C, 13 and 16 May 1998, CL 3091, coll. D. A. & J. T . Polhemus ( JTPC, BPBM) ; 1 female, small stream nr. Lan Hanh, 31 km E. of Di Linh , 825 m, 11°36'15"N, 108°19'17"E, water temp. 24°C, 27 Mar.2001, CL 3094, coll. J. T . Polhemus ( USNM) . Kontum Prov.: 2 males, 2 females, Ialing Rapids, 64 km SW of Kontum, 4 km W. of Ialy , 500 m, 14°12'02"N, 107°48'42"E, water temp. 24°C, 8 Mar.2001, CL 4285, coll. J. T . Polhemus & P. Nguyen ( USNM) . Quang Ngai Prov., 10 males, 10 females, Nuoc Xi stream, 123 km NE of Kontum on Hwy. 24, 120 m, 14°43'10"N, 108°35'48"E, water temp. 26°C, 18 Mar.2001, CL 4299, coll. D. A. Polhemus, J. T . Polhemus & P. Nguyen ( USNM) . Binh Dinh Prov., 1 male, 1 female, spring fed stream on E. side of An Khe Pass, 15.5 km E. of An Khe on

34

apex dark yellow; hemelytra dark blackish brown with tiny pale asperities, outer half of embolium dark yellow, wing membrane in submacropterous forms poorly defined, dark brown; abdominal laterotergites dark yellow, extreme posterior margins dark brown. This species may recognised by its moderate size for the genus, the predominantly dark hemelytra which lack yellow markings except on the outer half of the corium, the projecting tab on the lateral margin of male abdominal left paratergite V ( Fig. 35 ), and the distinctive male genitalic strucutures ( Fig. 27 ).

Distribution. — Montandon (1897a) described H. ovatus from a single specimen taken in the vicinity of Lakhon, in northern Laos, by François Jules Harmand, a French doctor who from 1877–1878 made a traverse of the country lying between Lakhon, on the Mekong River, and Quang Tri, in modern Vietnam. Montandon did not indicate the sex of his Laotian holotype, and although this specimen was recently re-examined and discussed by Sites & Vitheepradit (2011), these latter authors did not indicate the sex in their publication either. We have contacted Eric Guilbert of the Muséum National d’Histoire Naturelle in Paris, where the holotype is held, who has confirmed that this specimen is a female, and has provided useful notes on its morphology. As noted by Sites & Vitheepradit (2011), H. ovatus is widespread in Indochina, with records provided by these authors for China (Hainan), Burma, Thailand, and Vietnam, to which we can now add a new record from Hong Kong as well. As explained below, records of H. ovatus for Malaysia (and perhaps elsewhere in Indochina) listed by these latter authors are misidentifications, and refer instead to the new species H. malayensis described herein.

Discussion. — Males of H. ovatus are easily recognised by the blunt, anteriorly projecting tab on the lateral margin of male left abdominal paratergite VI ( Fig. 35 ), which is very different in form from the hooked projection on the left abdominal paratergite VI in males of H. malayensis ( Fig. 34 ). No other species of Heleocoris so far known from Southeast Asia possess similar projections on male left paratergite VI. The male phallotheca also differs in shape between the two species, with the tip being more produced and evenly rounded in H. malayensis , and the distal internal sclerite of a different shape (compare Figs. 24 and 27 ). Females are by contrast far more similar, with the posterior margin of the subgenital plate being broadly concave in H. malayensis ( Fig. 32 ), rather than bearing a broad, V-shaped incision as in H. ovatus ; the latter character state has been confirmed on the basis of an examination of the holotype female by Guilbert in relation to illustrations of the subgenital plates of both H. ovatus and H. malayensis provided by the authors.

Although Sites & Vitheepradit (2011) provided records of H. ovatus from the Peninsular Malaysian states of Pahang, Terengganu, and Selangor, we have re-examined the Terengganu series and determined that it is in fact composed of specimens of H. malayensis (see paratype material listed under that species). Given that all other specimens of Heleocoris of appropriate size and colouration that we have examined from Peninsular Malaysia also represent H. malayensis rather than H. ovatus , we have concluded that the Malaysian records of the latter species listed by Sites & Vitheepradit (2011) are probably all misidentifications. In addition, because the above authors did not utilise male paratergite or genitalic characters in their taxonomic analysis, and therefore did not realise that two species were co-mingled under their concept of H. ovatus , we consider it probable that at least some of the specimens of “ H. ovatus ” that they list from southern peninsular Thailand may represent H. malayensis as well, since it appears that H. malayensis may occur as far north as Laos (Zettel, in litt.). As such, all of the extensive material listed as H. ovatus by Sites & Vitheepradit (2011) will need to be critically re-examined on the basis of the characters discussed above in order to determine which of these two species was represented at any given locality, and the distribution map for this species given in their Fig. 9 will need to be revised for the southern half of the distribution in question, given that some of the symbols likely depict populations of H. malayensis rather than H. ovatus .

Figures

Figs. 24–28. Heleocoris species, male phallotheca. 24. Heleocoris malayensis, new species, specimen from Malaysia, Terengganu, Sungai Brang. 25. Heleocoris montandoni Lundblad, specimen from Singapore, Nee Soon swamp forest. 26. Heleocoris nebulosus Montandon, specimen from Indonesia, Bali, Melangit River. 27. Heleocoris ovatus Montandon, specimen from Vietnam, Lam Dong Prov., Pongour Falls, CL 3091. 28. Heleocoris strabus Montandon, specimen from Thailand, Chiang Mai Prov., Huay Hia Creek, CL 2198.

Figs. 34, 35. Heleocoris species, male left abdominal paratergites. 34. Heleocoris malayensis, new species, specimen from Malaysia, Terengganu, Sungai Brang. 35. Heleocoris ovatus Montandon, specimen from Vietnam, Lam Dong Prov., Pongour Falls.

Figs. 31, 32. Heleocoris species, female terminal abdomen, ventral view, showing shape of subgenital plate. 31. Heleocoris montandoni Lundblad, specimen from Vietnam, Lam Dong Prov., CL 3094. 32. Heleocoris malayensis, new species, specimen from Malaysia, Perak, Kerunai River, CL 2078.

Figs. 2–10. Naucoris species, structural details of male genitalia. 2–4. N. sigaloeis La Rivers, specimen from NE Thailand. 2. Left paramere. 3. Right paramere. 4. Phallotheca. 5, 6. N. scutellaris Stål, specimen from Singapore, Lower Fort Peirce Forest. 5. Left paramere. 6. Right paramere. 7–10. N. minutus, new species, specimen from Singapore, Chestnut Drive. 7. Left paramere. 8. Right paramere. 9. Phallotheca. 10. Proctiger.