Naucoris obscuratus Montandon, 1913

Mbogho, Aaron Y. & Sites, Robert W., 2013, Naucoridae Leach, 1815 (Hemiptera: Heteroptera) of Tanzania, African Invertebrates 54 (2), pp. 513-513 : 530

Naucoris obscuratus Montandon, 1913

Figs 10 , 22 , 30

Naucoris obscuratus: Montandon 1913 b: 220–222 .

Diagnosis: Naucoris obscuratus is much flatter than the dorsally convex Macrocoris and Neomacrocoris and body length is only 6.5–8.7 mm. Further, males do not have abdominal tergites 7 and 8 modified, whereas those of the other genera have medial lobes with modifications that are species specific. Males have parameres that are well developed and crisscrossing ( Fig. 10 ), whereas Macrocoris has smaller parameres that do not cross and Neomacrocoris lacks parameres.

Material examined: TANZANIA: Kagera Region: Benako Reservoir , 2°28.081'S 30°51.355'E, 1492 m, 26.vii.2010, R.W. Sites & A. Mbogho, marginal vegetation on dam, L-1156 ( UMC; 1♀) . Kigoma Region: Nyakivaya Lake , ca 5 km N of Kasulu town, 4°16.455'S 30°26.111'E, 1165 m, 27.vii.2010, R.W. Sites & A. Mbogho, shallow small lake with heavy vegetation, L-1161 ( UMC; 2♂, 1 nymph) . Kilimanjaro Region: Jiwemawe Reservoir at Ndungu , 4°25.496'S 38°05.201'E, 515 m, 13.viii.2010, R.W. Sites & A. Mbogho, vegetated margins of reservoir & below spillway, L-1251 ( UMC; 2♂, 1♀, 5 nymphs) . Mara Region: Ushashi , ca 5 km N of Nyiendo, 2°00.540'S 33°55.241'E, 1344 m, 24.vii.2010, R.W. Sites & A. Mbogho, vegetated pond margins, L-1147 ( UMC; 3♂, 1♀, 3 nymphs) . Mbeya Region: Lake Nyassa, Itunga inlet, 9°35.094'S 33°56.769'E, 482 m, 4.viii.2010, R.W. Sites & A. Mbogho, heavy marginal vegetation at boat ramp, L-1208 ( UMC; 1♂) . Morogoro Region: Kikwawila River at Kikwawila , 8°05.630'S 36°43.362'E, 269 m, 8.viii.2013, R.W. Sites & G. Rwegasira, water lettuce, L-1629 ( UMC, 1♀) . Pwani Region: pond by Ruvu River W of Bagamoyo, 6°28.545'S 38°50.614'E, 2 m, 16.viii.2010, R.W. Sites & A. Mbogho, water lettuce and other vegetation, L-1263 ( UMC; 1♂, 2♀, 6 nymphs, 1 exuvium) . Tanga Region: Gomba River , 2 km S of Chekelei, 4°50.284'S 38°18.774'E, 412 m, 14.viii.2010, R.W. Sites & A. Mbogho, grassy overhangs in irrigation canal, L-1255 ( UMC; 2♂, 1♀) .

Distribution: In the original description, Montandon (1913 b) reported the distribution as from Sudan to Lake Tanganyika, Egypt, Nigeria, and South Africa, and this was largely repeated by Poisson (1967). The East African countries of Uganda and Kenya were added by Montandon (1914) and Poisson (1963), respectively. The Republic of the Congo was added in the description of the subspecies N. o. nanus (Poisson 1960 a). West Africa was added ( Linnavuori 1971) and was followed by specific country records for Ivory Coast, Ghana, Nigeria, and Chad (Linnavuori 1981). During this study, N. obscuratus was found in scattered locations throughout Tanzania. More specifically, it was collected from eight localities in Kagera, Kigoma, Kilimanjaro, Mara, Mbeya, Morogoro, Pwani, and Tanga regions.

Discussion: This species is common in eutrophic rivers and normally is found among vegetation and debris ( Linnavuori 1971) in rivers, lakes, and pools (Linnavuori 1981). N. obscuratus is the only member of the genus Naucoris known from Tanzania. Even though N. obscuratus has been recorded from Sudan to South Africa, we collected it at only a few localities in Tanzania. Montandon (1913 b) listed this species from six localities, including “ Hego Tanganika”, which Poisson (1967) repeated and referred to the Tanganyika record as “lac Tanganyika”. Because Lake Tanganyika borders four countries, this record was not specific to a particular country. Thus, the collections reported here represent the first definitive records of N. obscuratus from Tanzania. Our determination of N. obscuratus is based on comparison with specimens identified by Linnavuori and that our specimens agree with the Linnavuori (1971) redescription, although our specimens are slightly longer than 8.0 mm that he reported. Our determination is provisional until the identities of N. fuscipennis and N. planus are clarified.

Figures

Figs 9–14. Male genitalia: (9) Macrocoris flavicollis, (10) Naucoris obscuratus, (11) Neomacrocoris karimii, (12) Neomacrocoris bondelaufa, (13) Neomacrocoris parviceps, (14) Neomacrocoris vuga. Abbreviations: LP – left paramere, RP – right paramere, ph – phallosoma, ve – vesica. (Figs 11–14 are reproduced from Sites & Mbogho (2012), with permission by Magnolia Press.)

Figs 20–22. (20) Macrocoris flavicollis female from L-1260, (21) Macrocoris laticollis male from L-1156, (22) Naucoris obscuratus female from Lake Rukwa,Tanzania.Sizes are proportionate among figures.

Fig.30.Distribution maps of13 speciesof Naucoridae known from Tanzania.Notincluded is Neomacrocoris usambaricus, which was recorded from West Usambara. (Map for N. bondelaufa and N. vuga is reproduced from Sites & Mbogho (2012), with permission by Magnolia Press.)