Enithares atra Brooks

Enithares atra Brooks

(Figs. 11, 12, 17, 22)

Enithares atra Brooks 1948. J. Kansas Entomol. Soc., 21: 48, fig. 11. Holotype, male, New Guinea, Rigo, Luglio, in SEMC.

Material examined. PAPUA NEW GUINEA, Central Prov.: 5 males (holotype and paratypes), 7 females (allotype and paratypes), Rigo, Luglio, 1889, L. Loria (SEMC, USNM ex JTPC); 3 males, 8 females, Owen Stanley Range, trib. to upper Mimani River, 0.8 km. W of Dorobisoro, 500 m., 9°27′39′′S, 147°54′56′′E, water temp. 23.5 °C., 9 October 2003, 08:30–12:30 hrs., CL 7264, D. A. Polhemus (USNM, BPBM); 2 males, 5 females, 2 immatures, Owen Stanley Range, trib. to upper Mimani River, 1.70 km. NE of Dorobisoro, 535 m., 9°27′25′′S, 147°56′15′′E, water temp. 23.5 °C., 7 October 2003, 13:00–15:00 hrs., CL 7260, D. A. Polhemus (USNM, BPBM). Milne Bay Prov.: 1 male, 9 females, headwater reach of Goilayoli River above crossing on road from Watunou to Huhuna, 11.5 mi. ENE of Alotau, 275 m., 10°18′43′′S, 150°37′16′′E, 6 April 2002, 10:00–13:00 hrs., CL 7161, D. A. and J. T. Polhemus (USNM); 7 females, Pini Range, spring and streamlet nr. old Duabo mission station, 300 m., 10°25′05′′S, 150°18′24′′E, water temp. 25° C., 9 April 2002, 14:00–15:00 hrs., CL 7170, D. A. and J. T. Polhemus (USNM, BPBM); 3 females, Sagarai River basin, Bwaona River, E. of Mila village, 90 m., 10°30′14′′S, 150°18′50′′E, water temp. 27–29° C., 7 April 2002, 10:45–12:45 hrs., CL 7165, D. A. and J. T. Polhemus (USNM); 6 males, 2 females, Cloudy Mountains, headwater tributary to upper Watuti River, S. of Gelemalaia village, 715 m. 10°29′50′′S, 150°13′58′′E, water temp. 22° C., 10 April 2002, 16:00–17:30 hrs., CL 7175, D. A. Polhemus (USNM, BPBM); 2 males, Cloudy Mountains, rocky stream 0.6 mi. above Gadowalai village, S. of Gelemalaia, 135 m., 10°28′57′′S, 150°14′27′′E, water temp. 24.5° C., 12 April 2002, 10:00–10:30 hrs., CL 7176, D. A. Polhemus (USNM, BPBM); 9 males, 21 females, Engineer Group, Tubetube Island, small stream above Samoa, 15– 45 m., 10°35′03′′S, 151°11′36′′E, water temp. 28° C., 19 January 2004, 09:00–10:30 hrs., CL 7299, D. A. and J. T. Polhemus (USNM, BPBM).

Discussion. Enithares atra was originally described from a series of 12 specimens taken by Loria at in the Rigo district, along the south coast of New Guinea southeast of Port Moresby. Brooks (1948) stated that the type series of E. atra was in USNM, but Lansbury did not find it there, and Byers later confirmed to him by correspondence that it was in Kansas at SEMC. Thus, when preparing his monograph, Lansbury did not see the actual holotype of this species, but only one male paratype. He instead based his re-description on material from Lae and Finschhaven, localities lying on the north coast of New Guinea far from from the original Rigo type locality.

A disjunct distribution of this type is quite atypical for most species of aquatic Heteroptera in New Guinea, which led the author to suspect that Lansbury (1968) may have misinterpreted the species concept for E. atra. A comparison of Brooks’ (1948) Figure 11 to material collected by the author in the vicinity of Dorobisoro in the Rigo District, near to the original type locality, shows that the male genitalic structures match well, particularly in regard to the shape of the slender, tapering LABP, which is partially depicted by Brooks. A more detailed illustration of the male genitalia for one of these more recently collected E. atra specimens is provided in Fig. 17.

Lansbury (1968) also did not indicate which specimens he made his illustrations from, although there are three possibilities based on the material he listed: a male paratype from Rigo at BMNH; a male and female from Lae in Oxford; or a series of 5 males and 9 females from Finschhafen in the South Australian Museum. The genitalia of male specimens collected more recently by the author in the vicinity of Madang match Lansbury’s figures, particularly in regard to shape of the LABP, which terminates in a slightly expanded, truncate apex (Fig. 17, compare to Fig. 273 in Lansbury 1968), so it is clear that he illustrated a north coast male, from either the Finschhafen or Lae series. These north coast populations are in fact an undescribed species, treated herein as E. orsaki n. sp.

As now understood, E. atra is a lowland species occurring in the southern foothills of the Papuan Peninsula, and ranging eastward through the islands east of Milne Bay as far as Tubetube, in the Engineer Group (Fig. 22). All previous records of this species from the north coast of New Guinea, including those in Lansbury (1968), are referable to E. orsaki n. sp. (see following description and discussion). Based on verified collections, E. atra occupies the South Papuan Peninsula Foreland area of freshwater endemism (Area 30) as defined by D. Polhemus & Allen (2007).