Nannogermalus webbi, Kóbor, 2023

Kóbor, Péter, 2023, The New Caledonian endemic geocorine bug genus, Nannogermalus is not monotypic anymore (Heteroptera: Lygaeoidea: Geocoridae), Zootaxa 5382 (1), pp. 43-54 : 49-51

Nannogermalus webbi sp. nov.

Figures 7–9 , 11 , 14 .

Nannogermalus marmoratus (misidentification: Kóbor & Kondorosy (2020)): 364 .

Type material. Holotype: f ( BMNH): “Up. Houadou R., / New Caledonia. / 4. VIII. 1914. / P. D. Montague. / 1918–87” .— Paratypes: 2 m, 2 f ( BMNH): “Up. Houadou R., / New Caledonia. / 4. VIII. 1914. / P. D. Montague. / 1918–87” , 1 m ( USMB): “ NEW CALEDONIA / 22°01.9’ S 166°28.0’ E / Dzumac Mts 900 m / (Mt Ouin road junction) / 29. 12. 2006 bitting / leg. R. Dobosz // 5915 / 100449 / coll. Upper Silesian Museum (USMB) Bytom, Poland” .

Description. Colouration. Body generally ochraceous, with fuscous decoration. Head. Ocelli reddish with surroundings slightly infuscate. Venter of head with pale fuscous spot extending from base to antenniferous tubercles. Thorax. Pronotum with pale fuscous longitudinal line at both lateral margins, pronotal callosities brownish. Scutellum with an irregular spot at trifurcate carina medially, its extent and colour variable. Corium of hemelytron semi-hyaline with narrow, irregular spots of various extent near apex of claval commissure, at basal third of punctures along R-M and along apical half of corium-membrane margin. Thoracic pleurites fuscous except prothoracic collar, a spot dorsolaterally near pronotal callosities, supracoxal lobes, peritreme and ventral half of metepimeron. metafemora with subapical rounded fuscous spot dorsally. Abdomen with posterior margin of tergites narrowly brownish, interrupted by the ochraceous curvature of the sutures between tergites IV–VI. Abdominal venter undecorated.

Structure. Head pentagonal with eyes slightly stylate; vertex conspicuously declivent; integument rugose with decumbent pubescence and few punctures at middle of vertex. Eyes slightly stylate, eye stalks slightly erect; ocular sulcus complete, well-defined. Head length to width: 1: 2.46. Ocelli situated near ocular sulcus, distance between ocelli subequal to compound eye-ocellus distance, ratio: 1: 0.93. Ratio of length of antennomeres: 1: 1.76: 1.59: 1.76. Ratio of length of labiomeres: 1: 0.90: 0.77: 0.87. Thorax. Integument of thoracic dorsum covered densely with fine decumbent pubescence. Pronotum campanulate with lateral margins straight and posterior margin slightly convex medially; ratio of pronotum length to width: 1: 1.6. Punctuation of pronotum relatively dense and evenly distributed; callosities, humeral angles, and posterior margin narrowly impunctate. Pronotal callosities divided by a narrow slightly, but conspicuously elevated, longitudinal median keel ( Fig. 11 ). Scutellum with trifurcate carina narrow, elevated, slightly constricted medially; ratio of scutellum length to width: 1: 1.4. Integument of scutellum deeply punctate except trifurcate carina. Clavus with margins subparallel, claval commissure minute, but distinct; length of claval commissure to length of scutellum: 1: 3.13. Scutellar margin with punctures in apical third, corial margin punctate at entire length. Corium deeply punctate along Cu and with a S-shaped row of puncutres near R-M. Exocorium widening from basal third of length apically. Membrane surpassing well the apex of abdomen; membrane with slightly visible, simplified venation. Thoracic tergites and pleurites densely punctate except supracoxal lobes, surroundings of peritreme and metepimeron. Abdomen. Integument of abdomen with fine, decumbent pubescence. Sutures of abdominal tergites IV/V and V/VI moderately curved, apices rounded; margins of sutures unarmed.

Measurements (holotype, in mm). Total body length: 3.04; head length: 0.39; head width: 0.96; distance of ocelli: 0.31; length of antennomeres I–IV: 0.17, 0.30, 0.27, 0.30; length of labiomeres I–IV: 0.31, 0.28, 0.24, 0.27; pronotum length: 0.75; pronotum width: 1.20; scutellum length: 0.50; scutellum width: 0.70; length of claval commissure: 0.16.

Differential diagnosis. Besides its variable, yet characteristic colouration pattern, N. webbi can be recognized by its medially constricted scutellar trifurcate carina (trifurcate carina is interrupted by puntures in N. marmoratus , evenly elevated in N. herczeki and basally flared in N. pallgergelyi ).

Etymology. Patronym. The species was named after Michael D. Webb, excellent British hemipterist, curator of the Hemiptera collection at BMNH as a token of the gratitude for the tremendous help at the start of the author’s career.

Distribution. Individuals of N. webbi were collected in the upper reaches of the Houaïlou River (= Up. Houadou R.) and in the Dzumac Mountains, near Mont Ouin.

Notes. The specimens on which the description of the species was based (besides the one borrowed from USMB) were originally thought to be representing the intraspecific variation of N. marmoratus , thus they were included among its paratypes ( Kóbor & Kondorosy 2020). However, the novel morphological data concludes that characters suspected to display intraspecific variability are rather of species level differences.

Figures

FIGURES 7–9. Nannogermalus webbi sp. nov. (Holotype, BMNH):7. dorsal habitus, 8. lateral view, 9. detail of peritreme(scale for figures 7–8 = 1 mm; figure 9 is not to scale).

FIGURES 10–13. Morphological characteristics of Nannogermalus species: 10. head of N. pallgergelyi, 11. pronotum of N. webbi, 12. tuberculate margin of abdominal tergites in N. pallgergelyi, 13. tarsal claw and appendages in N. pallgergelyi (images not to scale).

FIGURES 14–15. Distribution map of Nannogermalus species (14; coordinates for N. webbi are rough estimates based on literature data) and habitat photo of N. pallgergelyi sp. nov. (15).