Hygropetrocoris Sites, NEW GENUS
Creators: name: Sites, Robert W.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Naucoridae
Hygropetrocoris

description: Hygropetrocoris Sites NEW GENUS
Figs. 1–4
Type species. Hygropetrocoris guyana Sites NEW SPECIES
Description. Length 8.96–9.20 (mean = 9.08), maximum width 5.60–5.84 (mean = 5.72). Body ovate, parallelsided, broadly rounded anteriorly, narrowly rounded posteriorly, macropterous; widest across embolia; dorsally head and pronotum light colored but heavily speckled with dark brown punctures; scutellum patterned with light and dark brown and black, wings patterned with white, brown, and black; membrane black (Fig. 1). Non-uniformly coarsely punctate throughout. Pronotum and scutellum irregularly tumescent.
Head. Head declivent ca. 70o with respect to long axis of body (Fig. 2 B); not continuous with lateral margin of pronotum (Fig. 1); compound eyes bulging, elevated above level of vertex (Figs. 2 B, C), inner margin convex when viewed from above (Fig. 1) and divergent when viewed from front (Fig. 2 C); series of four setal rosettes paralleling inner margin of eye; posterior margin of head slightly convex between eyes (Fig. 1); layer of black recumbent hairs appressed to occiput at midline and continuing around side under eye; labrum broad, rounded, well-developed (Figs. 2 B, C); rostrum short, three visible segments, first visible segment partially concealed behind labrum, each subsequent segment progressively narrower (Fig. 2 B), reaching to near anterior margin of prothoracic coxae; maxillary plate impubis with distal margin nearly straight; antennae brown, segment one short and conspicuous, two and four subequal in length, three longest, segments three and four hirsute.
Thorax. Pronotum nearly straight behind head (Fig. 1); transverse sulcus setting off band in posterior 1/4; transverse band ending at anterior end of clavus, end tumescent and with tuft of dark setae; anterior 3/4 with profuse dark punctation throughout; brush of elongate sensory setae on anterior surface behind eye; lateral margins smooth, convex; posterolateral corners broadly rounded; row of four to five clusters of stiff dark setae near lateral margin (Figs. 1, 2 B), sparse erect single erect setae scattered throughout lateral 1/3; posterior margin straight; pronounced tumescences in anterior 3/4 behind eye, midlateral, and on midline near transverse sulcus. Propleura meeting at midline (Fig. 1), anterior margin joined to prosternum; prosternal midline with carina between coxae. Scutellum large, irregularly and coarsely punctate, raised above level of wings, broadly tumescent, erect curved black setae in longitudinal row of tufts, patterned with light and dark brown, lateral margins slightly sinuate (Fig. 1). Mesosternum flat, continuous with mesepisternum except for lightly pigmented line of fusion. Mesosternellum broadly pointed. Metasternellum (=metaxyphus) transverse; strongly acuminate at posterior midline; with strong, narrow, midventral ridge. Hemelytra finely punctate throughout, with distinct clavus and embolium (Fig. 2 A); clavus with longitudinal intraclaval suture (Fig. 2 A) between claval suture and scutellum, claval commissure with longitudinal ridge; embolium with lateral margin mostly straight, arcuate at ends; embolar suture sinuate; patterns of erect curved black setae in rows, tufts, and singular on hemelytra except membrane (Fig. 2 A); membrane black, finely punctate. Hindwings well-developed.
Legs. Foreleg with femur broad, strongly widened posterobasally, distal half of anterior margin excavated, anterior margin with thick band of setae becoming paired in basal half; tibia narrow, with pronounced tooth in basal third; tarsus immovable, one-segmented; pretarsal claw single, minute, triangular (Fig. 2 D). Middle and hind trochanters and femora flattened and glabrous, femora with sparse elongate pale hairs and row of minute reddish brown spines on posterior margin; middle femur slightly curved dorsad following curvature of venter; middle and hind tibiae with numerous stout reddish brown spines and continuous circlet of spines at distal end except on dorsal side. Middle tibia gradually widening distally; without pad of hairs on ventral surface; two rows of posteroventral heavy spines, multiple rows of anterior heavy spines, row of posterodorsal swimming hairs. Middle tarsus threesegmented, tarsomere one short, acuminate, and produced beneath base of tarsomere two. Hind leg with tibia elongate, thin, multiple rows of spines on anterior and posterior margins, posterodorsal swimming hairs on tibia and tarsus; tarsus three-segmented, tarsomere one short, acuminate, and produced beneath base of tarsomere two, two long, three longer. Middle and hind pretarsi darkly colored; with short empodia; claws symmetrical, long, evenly curved, each with rounded basal tooth. Meso- and metathoracic coxae covered with ventromesal setae, becoming elongate distally.
Abdomen. Dorsally dark brown to black medially, connexiva pale yellow. Connexiva with margins smooth; posterolateral corners of II–IV narrowly rounded, V–VI broadly rounded, VII broadly acute; posterior third of III– VII with tuft of black setae near margin, III–V with scattered black setae mesad of tuft, III–VIII with marginal fringe of pale setae. Accessory genitalic process of mediotergite VI absent (Fig. 3 A). Medial lobes of VIII (pseudoparameres) large, black, angled posterolaterally, extending over lateral lobes (Fig. 3 B). Abdomen ventrally generally covered with fine, light brown setae; with glabrous pale yellow lateral band; posterior margin of V asymmetrically concave on left side (Fig. 1). Transverse glabrous patches on at least II-VI, patches paired on III–V. Spiracles III–VI evident between and slightly anterior to paired glabrous patches.
Diagnosis. The most striking attributes of this insect are the (1) nearly vertical head is relatively small and apparently more mobile with respect to the prothorax than in most other naucorids, (2) bulging compound eyes, (3) tufts of setae around the perimeter of the insect, (4) tumescent pronotum and scutellum, and (5) pattern of black setae on the hemelytra and scutellum.
Taxonomy. Five subfamilies of Naucoridae currently are recognized. Hygropetrocoris is hereby assigned to Cryphocricinae, Ambrysini. The insect does not have (1) the ventral thoracic carinae characteristic of Limnocorinae, (2) the tibial pad of setae, mid-ventral abdominal band of setae, front of the head folded posteroventrally, and other features characteristic of Laccocorinae, nor (3) the rostrum arising from a deep excavation set back from the anterior margin of the head characteristic of Cheirochelinae, which is restricted to the Old World based on known taxa. This leaves the New World subfamily Cryphocricinae and the cosmopolitan Naucorinae. The propleura wrap ventrally and extend over the prosternellum to touch at the midline, which is a characteristic found in Ambrysini, and the pseudoparameres are enlarged and directed posterolaterad which is found in Carvalhoiella, Ambrysus montandoni La Rivers and A. maldonadus La Rivers.
Despite its aberrant physiognomy, Hygropetrocoris seems most closely related to two groups of Ambrysini: (1) Ambrysus montandoni and A. maldonadus and (2) Carvalhoiella. Ambrysus montandoni and A. maldonadus have features that distinguish them from congeners and will be removed from Ambrysus in an upcoming publication with Higor Rodrigues. Carvalhoiella originally was placed in Ambrysinae [subsequently ranked as a tribe within Cryphocricinae (Štys & Jansson 1988)]. Nieser (1975) transferred Carvalhoiella to Naucorinae, Naucorini, but later transferred it back to Ambrysinae after examining specimens and describing C. stysi Nieser, Pelli & Melo (Nieser et al. 1999). Hygropetrocoris, Carvalhoiella, A. montandoni, and A. maldonadus share enlarged, posterolaterally-directed pseudoparameres (median lobes of tergum 8), loss of setation on some mediosternites, and a very shallow or no invagination of the head into the anterior margin of the pronotum. Together with Cataractocoris, all share a wide, marginal, glabrous, ventral abdominal band. Autapomorphies of Hygropetrocoris are the bulbous eyes, nearly-vertical head orientation, hemelytral hair lines and patches, stout marginal tufts of setae from the pronotum to the abdominal segments, and the profemur excavated distally with a corresponding tooth on the protibia (see Table 1). The excavated profemur and toothed protibia might be restricted to only males because similar modifications of the prothoracic legs is a sexually dimorphic character in many species of the Asian genera Cheirochela, Coptocatus, and Gestroiella (Cheirochelinae). Females of Hygropetrocoris are not known.
Discussion. The bulbous eyes, sensory hairs, and negligible invagination of the head into the pronotum suggest the head is more freely movable with respect to the pronotum than in other naucorids in which the head is relatively fixed and mostly acts in concert with the prothorax. This along with its irregularly shaped body surface and mottled color pattern are better suited for a terrestrial existence rather than living underwater, and its general appearance is reminiscent of Gelastocoris. The habitat in which these specimens were collected was on a seepage over granite bedrock with detritus, algae, and fallen leaves (Fig. 4). It was collected with a diverse community of hygropetric beetles including Anodocheilus sp., Copelatus sp., Fontidessus ornatus Miller, Fontidessus aquarupe Miller and Montano, Laccophilus sp. (Dytiscidae), Anacaena sp., Berosus avernus Oliva, Enochrus sp., Notionotus sp., Oocyclus floccus Short and García, Oocyclus petra Short and García, Oocyclus trio Short and Kadosoe, Oocyclus coromoto Short and García, Paracymus sp., Tobochares sulcatus Short and García, Tropisternus chalybeus Laporte de Castelnau (Hydrophilidae), and Liocanthydrus clayae (J. Balfour-Browne) (Noteridae) (A.E.Z. Short, pers. com., field notes and database at http://creac.kubiodiversityinstitute.org/collections). Other naucorid genera with similar habitat associations have been described recently. Specifically, in Indochina, Namtokocoris can be found completely immersed beneath sheeting water of waterfalls but also on wet rock surfaces that only are sprayed with mist from the waterfall (Sites & Vitheepradit 2007). In India, Diaphorocoris and Pogonocaudina were collected out of water on wet rock surfaces during the dry season (Sites et al. 2011), although they might also occur in the film of water of waterfalls at times of the year when more water is available. All of the known Old World genera that have adapted to waterfall or hygropetric habitats are in the subfamily Laccocorinae. In Mesoamerica, Cataractocoris of the subfamily Cryphocricinae occurs in waterfalls and other torrential habitats. Carvalhoiella in South America has been recorded from crevices in rocks of waterfalls (Nieser et al. 1999), and Daniel Reynoso- Velasco and I have collected Interocoris mexicanus (Usinger) in similar habitats in Chiapas, Mexico, although this species was described from a muddy river bank (Usinger 1935).
Etymology. The generic name " Hygropetrocoris " is in reference to the bug's wet rock habitat and derives from Greek with hygro for wet, petro for rock, and coris for bug.
Material examined. See species localities.
description: Published as part of Sites, Robert W., 2015, New taxa of Cryphocricinae (Heteroptera: Naucoridae) from the Guiana Shield: Hygropetrocoris Sites, n. gen. and two new species of Ambrysus Stål, pp. 427-438 in Zootaxa 4033 (3) on pages 428-431, DOI: 10.11646/zootaxa.4033.3.7, http://zenodo.org/record/239105