Kiwisaldula, Larivière & Larochelle, 2016

Larivière, Marie-Claude & Larochelle, André, 2016, Aoteasalda and Kiwisaldula, two new genera of Saldidae (Hemiptera: Heteroptera), with a key to New Zealand genera and a new synonymy in Zemacrosaldula, Zootaxa 4085 (4), pp. 451-480 : 459-460

Kiwisaldula new genus

Type species. Saldula parvula Cobben, 1961 , by present designation.

Description. Body length 2.75–4.34 (3.44) mm; short-ovate, short-pyriform or elongate-ovate. Dorsal colour somewhat marbled; largely dark, with broadly pale or, more rarely, narrowly pale lateral margins of pronotum, mostly well-developed coalesced or individual pale markings on hemelytra, including a distinct eyespot subbasally on endocorium next to a large apostrophe-shaped mark on exocorium. Subbrachypterous to macropterous. Head not closely appressed to thorax (eyes distinctly separated from thorax), with three pairs of long trichobothrium-like setae (two dorsally on mandibular plates, two near preocellar furrows, two near preocellar spots). Frons with barely distinct to moderately developed longitudinal furrow medially. Ocelli slightly elevated from surface of vertex, separated by the diameter of one ocellus or less, closer to each other than to eyes. Preocellar spots distinct, paler than surrounding area, subtriangular to crescent-shaped, narrowly to broadly touching eyes (by one ocellus width or more), slightly extending or not in front of ocelli. Preocellar furrows present, about as deep as or slightly deeper than longitudinal frontal furrow. Preocular spots usually distinct, paler than surrounding area. Transverse swelling (postclypeus of Cobben) variously swollen, slightly to strongly developed; lateral portions contiguous near facial midline or, more rarely, separated by a very narrow gap (narrower than in Zemacrosaldula or Aoteasalda ). Mandibular plates barely to strongly developed. Maxillary plates slightly to strongly developed. Antennae nearly bicoloured, with segments I–II largely pale compared to segments III–IV; segment II usually 2.0–2.3x longer than I (1.1–1.3x in K. stoneri ), clothed over entire length with short setae (slightly shorter than or subequal to segment width), with some longer setae in apical half; segments III–IV not wider than apex of segment II, with short setae and a number of longer setae (subequal to or longer than segment width). Thorax. Pronotum 0.5–0.8x as long as scutellum medially; subtrapezoidal; lateral margins ( Figs 9–12 ) subrectilinear to moderately convex, rarely slightly sinuate-concave, usually broadly pale (pale area 1.5– 2x as wide as antennal segment II), rarely narrowly pale to almost completely dark ( K. stoneri ), variously explanate, and separated from disc by a longitudinal furrow; collar present, continuous (not interrupted medially), delimited posteriorly by a row of punctures; calli somewhat strongly raised (more so than in Aoteasalda or Zemacrosaldula ), well differentiated from disc, contiguous, forming a transverse elevation with a median pit, delimited posteriorly by a row of punctures not reaching lateral margins of pronotum. Thoracic underside: xyphus 2 short (much wider than long), subtriangular. Legs: hind tibiae with subapical comb; hind tarsal segment II 0.7–1.1x as long as segment III. Hemelytra without a line of four spots along R vein; pubescence short to moderately long, reclined (mostly) to semi-erect, mostly golden brown (sometimes silvery in places), usually thicker, longer and more densely distributed on hemelytra (especially clavus and endocorium); clavus and corium moderately pruinose (pruinosity often reduced on exocorium); costal margin slightly convex along entire length; costal fracture straight or slightly curved, very short or nearly reaching apex of R vein, barely extending towards clavus from membrane; embolar modification of female indistinct or barely developed; subapical pale spot of clavus usually present; membrane with four, sometimes three, reduced to wellformed cells, cell 2 about as long as cell 3, cell 4, when present, subequal in length, longer, or shorter than cell 3; hypocostal ridge simple; secondary hypocostal ridge absent. Abdomen. Venter: male, dark, with or without posterior margin of segments narrowly pale; female, dark medially, broadly (mostly) or narrowly pale laterally. Paired eversible glands present; when externally visible, one gland located on each side near posterior margin of segment VII. Male parandria ( Figs 25–28 ) elongate, narrowly or broadly subtriangular; tip acutely rounded; inner membrane present along basal half of inner margins. Male paramere ( Figs 21–24 ) with or without barely distinct processus sensualis; processus hamatus at an obtuse angle with corpus paramerus (as opposed to a right angle in Zemacrosaldula ); dorsal margin bearing short to moderately long setae. Male aedeagus containing four pairs of sclerites ( Fig. 30 , K. parvula ), two basally joined, larger, branched median sclerites, their outer branch slightly curved but not hooked apically, and six individual, smaller, simple anterolateral sclerites. Male filum gonopori coiled 1.5 times ( Fig. 31 ). Female subgenital plate (segment VII, ventrally) with posterior margin produced caudally, truncate medially. Ovipositor with gonapophyse 1 distinctly serrate. Spermathecal pump flange present. Gynatrial ring gland unsclerotised.

Remarks. The generic name Kiwisaldula is derived from Kiwi- (vernacular name of flightless bird native to New Zealand or nickname of a native or resident of this country) and Saldula (name of a similar-looking genus). The main morphological characters unifying the species of Kiwisaldula are listed here, with generic level apomorphies from Polhemus (1985) in italics: size small to moderate (2.75–4.34 mm); dorsal colour marbled, largely dark, with broadly pale or, more rarely, narrowly pale lateral margins of pronotum and mostly welldeveloped coalesced or individual pale markings on hemelytra, lacking a line of four pale spots along R vein; hemelytra with a distinct eyespot subbasally on endocorium next to an apostrophe-shaped mark on exocorium; antennal segment II rather short, clothed over entire length with very short setae, with some longer setae in apical half; frons with barely distinct to well-developed longitudinal furrow medially; lateral margins of pronotum explanate, separated from disc by longitudinal furrow; calli of pronotum forming a transverse elevation with a distinct median pit and delimited posteriorly by a row of punctures not reaching lateral margins; mostly subbrachypterous or brachypterous; membrane with four, sometimes three, reduced to well-formed cells; embolar modification of female indistinct or barely developed; hind tibiae with subapical comb; male aedeagus with anterolateral sclerites; processus sensualis of male paramere indistinct or barely developed (not tumid); filum gonopori of male coiled 1.5 times; female abdominal venter not concolorous with underside of thorax, broadly or sometimes narrowly pale laterally.

The male abdominal grasping plate was not studied in detail; preliminary observations in K. parvula indicate that it bears around 15 spines, an outer row of five to seven rather short, blunt spines and an inner group of roughly ten longer, sharper spines.

Limited quality material was available to study the gynatrial ring gland situated near the base of the female ovipositor but an obvious sclerotised ring, as in Aoteasalda or Zemacrosaldula , could not be seen in the half dozen specimens dissected.

Kiwisaldula species exhibit a high level of eunomic variability. Divergence from the standard eunomy is common even within populations. Tenerals or recently molted adults with a soft cuticle can be deceptively pale compared to fully mature adults; they may also have distorted male genitalia. Environmental factors also seem to be at play, cooler temperatures and/or higher humidity generally shifting the eunomic series towards the dark side of the sequence while the reverse produces lighter forms. These trends were also noted and briefly discussed by Larivière & Larochelle (2015) for species of the genus Zemacrosaldula . All species and most populations of Kiwisaldula will harbour a few very dark individuals with reduced hemelytral markings and very narrowly pale to almost completely dark lateral margins of pronotum.

When collecting in the field it is rather difficult to judge whether individuals sampled represent the standard eunomy or are mature enough so that their cuticle is hardened and body parts have taken their final shape and colour. Consequently, it is critical to collect enough individuals from a given population to have ‘good quality’ material to work from. In the authors’ experience at least 25 mature specimens are required and collections of 35– 50 specimens are ideal.

Nevertheless, there is sufficient overlap between the eunomic series of species treated in this paper to render this character nearly useless for species diagnosis, except in the case of K. stoneri and to some extent also K. parvula . In all cases, the ultimate criteria for species recognition are characters of the male genitalia.

While K. stoneri occurs inland only, other Kiwisaldula species are common in saline or brackish water environments around the coast of the North Island as well as along the margins of freshwater habitats. Kiwisaldula parvula and K. porangahau appear especially common in estuarine habitats but large populations can also be found inland. Kiwisaldula species are slightly to moderately heliophilous; they are often found in the shade and they remain active under cloudy or rainy conditions. Species of this genus favour sandy, muddy or silty substrates with little or no stone or gravel and at least some vegetation. In inland situations, Kiwisaldula species will often be found along the banks of sandy, silty or muddy side channels, pools or seepages away from the main water channel of rivers and streams with rather stony or gravelly banks where Zemacrosaldula or Aoteasalda species occur.

Figures

FIGURES 9 – 12. Dorsal view of Kiwisaldula species (males; legs and antennae omitted). Scale bar = 1 mm. (9) K. stoneri, (10) K. porangahau, (11) K. parvula, (12) K. manawatawhi.

FIGURES 25 – 31. Schematic view of Kiwisaldula species male genitalia. (25 – 28) Parandria, posterior view. (25) K. stoneri, (26) K. porangahau, (27) K. parvula, (28) K. manawatawhi. (29 – 30) K. parvula. (29) Anterior half of aedeagus, lateral view, (30) sclerites of aedeagus, ventral view. (31) Kiwisaldula species. Filum gonopori, lateral view.

FIGURES 21 – 24. Schematic view of Kiwisaldula species male genitalia: paramere, ventral. (21) K. stoneri, (22) K. porangahau, (23) K. parvula, (24) K. manawatawhi.