Nannogermalus, Kóbor & Kondorosy, 2020

Kóbor, Péter & Kondorosy, Előd, 2020, Nannogermalus Marmoratus: A New Endemic Big-Eyed Bug From New Caledonia (Heteroptera: Lygaeoidea: Geocoridae), Acta Zoologica Academiae Scientiarum Hungaricae 66 (4), pp. 361-368 : 362-363

Nannogermalus gen. n.

( Figs 1–2 )

Type species: Nannogermalus marmoratus sp. n.

Description. Head concave pentagonal in dorsal view. Eyes slightly stylate with ocular sulcus complete, well-defined. Vertex conspicuously slanted anteriad in lateral view. Vertex with three longitudinal furrows (most conspicuous in frontal view): two arched furrows situated medially to ocelli and a minute longitudinal furrow in the middle of vertex, extending to base of clypeus ( Fig. 2A ). Curved transversal furrows extending between subbasal part of clypeus and ocular sulcus. Clypeus with basal sutures distinct; divided in 1:2 ratio with transversal suture subapically ( Fig. 2A ). Antennomere I shortest, antennomeres II–III subequal, antennomere IV somewhat shorter than II–III. First three antennomeres cy- lindrical, segment IV conspicuously spindle formed. Venter of head deeply punctate. Labial trough open, V-shaped. Labiomere I not reaching base of head; labiomeres II–III subequal; labiomere IV shortest, reaching line of metacoxae. Thorax: Pronotum campanulate in dorsal view with slightly concave lateral margins, profile conspicuously gibbous. Surface with dense, deep irregular punctation. Pronotal callosities reduced to narrow, impunctate furrows, separated by a narrow longitudinal ridge. Humeral angles impunctate. Posterior margin with slight impressions near basal angles of scutellum. Scutellum sub-equilateral with margins slightly curved, apex sharply pointed; surface with dense punctation, similarly to pronotum; trifurcate carina T-shaped, somewhat widened in basal and apical angles, inter- rupted by few punctures medially. Hemelytron macropterous; membrane well developed, margin surpassing apex of abdomen. Clavus of hemelytron narrow, parallel sided; length of claval commissure less than half of median length of scutellum; scutellar margin with 4 punctures apically, corial margin completely punctate ( Fig. 2C ). Corium with a line of punctures along Cu and an arched line along M+R, continuing on apical corial margin laterad but not reaching apex; surface of intervannal areas rugose; apical margin of corium with slight impression by M; costal margin narrow. Prosternal margin collar-like, bulging with a line of punctures. Thoracic pleurites and sternites mostly with dense punctation, similar to pronotum except metapleurites above the MTSEA. Peritreme of MTSEA situated ventrolaterally, dorsal margin hardly exceeding line of supracoxal lobes; ostiole oblong, irregular; vestibular scar absent; evaporative area reduced to the surroundings of peritreme. Femora unarmed, length of tarsomere I subequal to sum of length of tarsomere II and III. Position of abdominal spiracles II–IV dorsal, V–VII ventral. Abdominal segments I–III inseparable; sutures of abdominal tergites IV/V and V/VI medially curved posteriad ( Figs 1A , 2C ). Apex of connexiva of segment VII protrusive ( Fig. 2D ). Genitalia: Male pygophore with dorsal opening rounded, lateral processes sharply pointed, apex of lateral process hooked. Para- meres with blade long and slender, conspicuously curved; crossing each other in X-form in situ. Female ovipositor short, not exceeding genital capsule.

Diagnosis. Pentagonal head with moderately stylate, kidney-shaped eyes and the medially curved sutures of abdominal tergites IV/V and V/VI clearly demonstrate that the genus is a representative of the family Geocoridae . The position of abdominal spiracles confirms that the genus belongs to subfamily Geocorinae . The proportions of scutellum, the parallel margins of clavus, the punctation of corium and structures of male genitalia suggest a close relationship to New Caledonian Germalus species. The structure of MTSEA resembles more to representatives of Geocoris , e.g. the Australian Geocoris lubrus Kirkaldy, 1908 (specimens examined by the senior author). Based on the available data the taxon is considered to be closely related to Germalus and allied taxa. Nevertheless, the exact placement of this genus within Geocorinae should be subject of a phylogenetic analysis (in progress).

Besides the minute size compared to other geocorine bugs of the archipelago, Nannogermalus can be delimited by the conspicuously slanted vertex; punctate venter of head; campanulate pronotum with furrow-like callosities and T-shaped carina of scutellum.

Etymology. Masculine generic name. The naming of the genus indicates its close relationship with the geocorine genus Germalus Stål, 1862 . Prefix “nanno-” comes from the Greek word “nannos” (small, minute) referring to the size of these insects: these insects are the smallest known representatives of big-eyed bugs.

Figures

Fig. 1. Nannogermalus marmoratus (paratype male, NHMW):A = dorsal habitus, B = lateral view Scales: A = 1 mm, B = 100 µm

Fig. 2. Details of Nannogermalus marmoratus (paratype male, NHMW): A = head in frontal view, B = head and pronotum, C = scutellum and hemelytron, D = abdomen. Scale: 100 µm