Zemacrosaldula whakarunga, Larivière, Marie-Claude & Larochelle, André, 2015

Larivière, Marie-Claude & Larochelle, André, 2015, Zemacrosaldula, a new genus of Saldidae (Hemiptera: Heteroptera) from New Zealand: taxonomy, geographic distribution, and biology, Zootaxa 3955 (2), pp. 245-266 : 258-260

Zemacrosaldula whakarunga new species

Zemacrosaldula whakarunga Larivière & Larochelle , new species. Holotype: male (NZAC) labelled “ NEW ZEALAND SD Carluke, Rai River 50m 4112 S 17335 E 27.II.2012 Larivière, Larochelle / Sandy-silty gravelly riverbank; within 2m from water[line] / HOLOTYPE [male symbol] Zemacrosaldula whakarunga Larivière & Larochelle, 2015 (red label). Paratypes: 6 males (1 LUNZ, 1 CMNZ, 1 MONZ, 3 NZAC) and 5 females (1 LUNZ, 1 MONZ, 3 NZAC) with same data as holotype, bearing blue paratype labels.

Description. Body length 4.31–6.28 (5.57) mm; broad-ovate ( Fig. 3 ). Dorsal colour largely black, sometimes with a very faint maroon hue, with uniformly dark lateral margins of pronotum and a few individual (not coalesced) whitish markings on hemelytra; frequently with combination of a pair of semilunate marks in basal third of corium and a small to medium size subquadrate medial mark at about midlength on exocorium. Facial colour ( Fig. 9 ) slightly to moderately contrasted. Head, pronotum, and scutellum strongly shiny, usually contrasting strongly against mostly dull hemelytra. Dorsal pubescence short, reclined to semi-erect, whitish, somewhat sparse and unevenly distributed. Dorsal microsculpture slightly rugulose on head, pronotum and scutellum. Head black. Face ( Fig. 9 ) pubescent. Transverse swelling yellowish brown to almost entirely black; lateral portions contiguous or, sometimes, separated by a narrow to rather wide dark gap near facial midline. Mandibular plates black or, less often, yellowish brown. Maxillary plates whitish yellow to yellowish brown, rarely obscure. Anteclypeus and labrum yellowish brown to dark brown, narrowly to broadly margined with black. Antennae 4.24–4.85x longer than pronotum + collar medially, largely dark; segment I mostly black with partial or complete yellowish stripe on one side, sometimes entirely black; segment II black, often shortly paler subapically, 2.18–2.35x longer than segment I; segments III–IV black. Thorax. Lateral margins of pronotum subrectilinear to slightly convex, uniformly black. Underside black, with moderately contrasting broadly or narrowly pale acetabulum I, broadly to very narrowly pale acetabulum II, narrowly pale to completely dark acetabulum III, and partially (posterior quarter to half) to completely dark lateral margins; rarely, if ever, with lateral margins almost completely pale; pubescence moderately dense, silvery, appressed (except for glabrous lateral margins). Legs largely dark; fore, mid, and often hind femora almost entirely black or thickly striped with black on ventral and often also dorsal side over most of length, otherwise whitish yellow to yellowish brown with some brown spots; tibiae with dark brown to black dorsal stripe over most of length (hind tibiae often infuscate only) and black subapical annulus, otherwise whitish yellow to yellowish brown with dark spines; hind tibiae about 2.77–2.86x longer than tarsal segments II+III combined; tarsal segment II darkened apically, otherwise whitish yellow to yellowish brown, segment III completely dark brown to black (often paler in basal half on hind tarsus); pretarsal claws rather short, about a third of the length of tarsal segment III. Scutellum black, 1.78–1.83x longer than pronotum + collar medially. Hemelytra: costal margin ( Fig. 3 ) more convex and embolium generally more explanate basally than in Z. australis or Z. kapekape ; corium ( Fig. 13 ) largely black with few irregular, individual (not coalesced), whitish markings; frequently with a pair of semilunate marks in basal third, one on each side of R vein (as opposed to Z. pangare ); endocorium with a line of four pale spots (often reduced to two or three) along R vein, a few additional speckles (often reduced) subapically along membrane; exocorium without coalesced markings, with few individual markings, a small to moderately large subquadrate medial mark at about midlength, and often a smaller irregular medial mark subapically (often reduced or absent); colour pattern in female consistent with that of male but regularly with larger subquadrate medial mark at about midlength on exocorium; pale markings in darker individuals strongly reduced in size and numbers, with line of two to four spots still visible but reduced to speckles; corium in darkest individuals almost entirely black and barely speckled; corium and clavus largely pruinose; basal and subapical pale spots of clavus present or absent; membrane brown to black basally, rarely with a pale mark near tip of clavus, brown medially within cells and around margin, pale within cells on each side of brown medial mark, and with dark brown to black veins. Abdomen. Venter black, with (both sexes) or without (male) posterior margin of most segments narrowly pale. Pubescence moderately dense (although sparser than in Z. australis or Z. kapekape ), silvery, appressed in both sexes. Male parandria ( Fig. 20 ) broadly subtriangular, obtusely rounded at tip; inner margins angular; basal margin straight. Male paramere ( Fig. 17 ) with distinct, well-developed processus sensualis bearing less than 10 setae; processus hamatus narrowly rounded and often slightly upturned at tip. Apical half of male aedeagus ( Fig. 22 ), in lateral view, with 3 main visible sclerites (elongate median sclerite; shorter Y-shaped anterolateral sclerite; smaller subtriangular anterolateral sclerite). Male filum gonopori (Fig. 25) coiled 1.25 times. Female subgenital (segment VII, ventrally) plate black with apical quarter to half pale or, sometimes, plate at most narrowly pale apically. Other characters as in generic description.

Geographic distribution ( Fig. 26 ). South Island, excluding southernmost areas and the west coast.

Material examined. A total of 228 specimens including types, from the following localities. South Island. BR —Boyle River, Dans Creek Bridge, Engineers Camp ( LUNZ); Fox River (Buller County) ( LUNZ); Nelson Lakes National Park (Lake Rotoiti, head ( LUNZ); Mount Robert ( LUNZ)); Punakaiki, Bullock Creek ( CMNZ). CO —Lowburn Valley mouth ( NZAC); The Remarkables, Rastus Burn ( LUNZ); Duntroon, Maerewhenua River ( NZAC); Junction of Danseys Pass Road & S Branch of Maerewhenua River ( NZAC); Palmerston, Shag River ( NZAC). KA —Hundalee, Conway River ( NZAC); Junction of Kowhai River & Postmans Road ( NZAC); Kahutara River mouth ( NZAC); Oaro Beach ( LUNZ). MC —Banks Peninsula (Birdlings Flat ( CMNZ); near Lake Ellesmere ( LUNZ)); Cameron River ( LUNZ); Craigieburn Forest Park, Dracophyllum Track ( NZAC); Craigieburn Ski Field ( LUNZ); Mount Algidus ( NZAC); Porters Pass, Lake Lyndon ( CMNZ, NZAC); South Highway 72, W of Staveley ( NZAC); Thomas River, N branch ( LUNZ). NC —Arthurs Pass National Park, Poulter River ( NZAC); Lees Valley, Ashley River bridge ( LUNZ); Napenape Scenic Reserve, Hurunui River mouth ( NZAC); Okuku River, 5km W of Loburn ( NZAC). NN –Aniseed Valley ( NZAC); Iron Hill, Iron Lake ( LUNZ); Karamea River mouth ( LUNZ); Lake Sylvester ( LUNZ); Lake Sylvester, Bushline Hut ( LUNZ); Little Sylvester Lake ( LUNZ); Oparara River ( NZAC); Pariwhakaoho River mouth ( NZAC); Pearce River Resurgence ( LUNZ); Pelorus Bridge Scenic Reserve ( NZAC). OL —Dart Hut ( NZAC); Greenstone River ( NZAC); Headlong Peak ( NZAC), South Basin Stream ( NZAC); Peak 2.5 km W of Mount Tyndall ( NZAC). SC –Temuka, Opihi River near Waiapi ( CMNZ). SD —Carluke, Rai River ( NZAC); Opouri River, junction with Tunakino Valley Road ( NZAC). WD — Mount Aspiring National Park (Arawata Bivouac ( LUNZ); Arawata River ( LUNZ)); Nelson Creek domain, beside Nelson Creek ( LUNZ).

Biology. Altitudinal range. Montane (mostly) to subalpine, more rarely lowland. Exceptionally coastal, in predominantly freshwater habitats located near the mouth of rivers that also harbour inland populations. Habitat. Occurs along stony-gravelly (or shingled) riverbanks riverbeds or, less frequently, lakeshores; mostly saxicolous; found mainly on gravel, stones or boulders near the water’s edge, usually within 0.5 to 3 m from the waterline, as well as on stones or boulders emerging from the water; mostly in sandy environments, also in moderately silty or clayish situations; primarily near moderate to fast running water, also near calmer water (e.g., side river channels or temporary backwaters); at higher altitudes, on wet screes and snowmelt patches. Often taken near water, on bare ground patches between stones or boulders, on bare ground with few scattered stones (e.g., silty, clayish or rather muddy flats and banks of otherwise stony-gravelly rivers and lakes), or, sparsely vegetated ground (e.g., at the margin of subalpine lakes). Occasionally collected near rocky seepages away from a main river channel. Nymphs live in the same habitat, on the ground surface between and under stones or among gravel, or, hiding at the base of plants. Seasonality. Adults collected from November to March; mating pairs observed in March; newly emerged adults (tenerals) collected in March; nymphs found from January to March. Food. Predator or scavenger. Behaviour. Jumps from stone to stone, flies short distances (usually less than 2 m), dashes quickly into the space between stones or into water when disturbed. Heliophilous; hides under and between stones or at the base of plants, in cloudy or rainy weather.

Remarks. The species name ‘whakarunga’ is from the Maori and means south or southern. It refers to the geographic range of this species which is restricted to New Zealand’s South Island where it is widely distributed.

Zemacrosaldula whakarunga is morphologically closer to Z. pangare than to other species in this genus. In addition to structural differences in the male genitalia, Z. whakarunga has an overall less shiny, more pubescent, more pruinose and more blackish appearance than Z. pangare . The hemelytral colour pattern, especially the frequent occurrence of a pair of semilunate marks in the basal third of the corium and a subquadrate medial mark at about midlength on the exocorium, is most often diagnostic for Z. whakarunga . See also Remarks under Z. pangare .

In eastern areas of the South Island, Z. whakarunga can be especially difficult to differentiate from darker, anomalous looking specimens of Z. australis (see Remarks under that species). In such cases as well as for darker forms of both species, with strongly reduced hemelytral markings, examination of the male genitalia is the only reliable identification method. Although found in lowland areas, especially along and near the mouth of large rivers originating from the Southern Alps (e.g., large South Island braided rivers), Z. whakarunga is habitually monticolous.

Figures

FIGURE 26. Collecting localities of Zemacrosaldula species, New Zealand.

FIGURES 1 – 4. Dorsal views of Zemacrosaldula species (legs and antennae omitted). Scale bar = 1 mm. (1) Z. australis, (2) Z. kapekape, (3) Z. whakarunga, (4) Z. pangare.

FIGURES 5 – 10. Facial views of Zemacrosaldula species. (5 – 7) Z. australis, (8) Z. kapekape, (9) Z. whakarunga, (10) Z. pangare.

FIGURES 13 – 14. Eunomy (left corium), with more frequently observed pigmentation patterns indicated by an asterisk (*). (13) Zemacrosaldula whakarunga, (14) Z. pangare.

FIGURES 15 – 24. Schematic views of male genitalia. (15 – 18) Paramere, ventral view. (15) Zemacrosaldula australis, (16) Z. kapekape (ph = processus hamatus), (17) Z. whakarunga (ps = processus sensualis), (18) Z. pangare. (19 – 20) Parandria, posterior view. (19) Z. australis, (20) Z. whakarunga. (21 – 22) Anterior half of aedeagus, lateral view. (21) Z. australis, (22) Z. whakarunga. (23) Sclerites of aedeagus, Z. australis, ventral view. (24 – 25) Filum gonopori, lateral view. (24) Z. australis, (25) Z. whakarunga.