Polistes (Gyrostoma) nigrosericans Bequaert, 1940, 2018

Selis, Marco, 2018, Revision of the genus Polistes Latreille (Hymenoptera: Vespidae: Polistinae) in the Philippine Islands, Zootaxa 4531 (4), pp. 507-531 : 508-510

Polistes (Gyrostoma) nigrosericans Bequaert, 1940 stat. nov.

( Figs. 1–6 )

Polistes tenebricosus var. (or subsp.) nigrosericans Bequaert 1940: 265 (key), 266, ♀, ♂ —“Los Baños, Luzon, Philippine Islands ” (holotype MCZ).

Diagnosis. Differentiated from other species by combination of the following characters: clypeus flattened and with rounded apical margin, gena about as broad as eye in lateral view, male apical flagellomere curved and tapering at apex, pronotal carina not lamellate, posterior face of propodeum broadly and shallowly depressed, punctation coarse, and wings orange.

Material examined. PHILIPPINES: LUZON: Apayao, Conner , VIII.2014, 2 ♂ ( MSVI) ; Apayao, Conner , IX.2014, 3 ♂ ( MSVI) ; Cagayan, St. Ana , X.2014, 1 ♀ ( MSVI) ; Ifugao, Banaue , III.2014, 1 ♀ ( MSVI) ; Isabela, Dindin , VIII.2014, 1 ♀ ( MSVI) ; Pandan , Catanduanes, VIII.2016, leg. Ismael Lumawig, 1♀ ( LDMLC) .

Distribution. Philippine Islands: Luzon ( Bequaert 1940; Carpenter 1996b)

Remarks. Bequaert (1940) originally described this taxon as a variety or subspecies of P. tenebricosus , then Saito et al. (2005) synonymized it along all other subspecies stating that “the subspecies category has no place in a phylogenetic system” and considering morphological characters of the subspecies sulcatus Smith, 1852 only. Comparing males of P. tenebricosus nigrosericans from Luzon with males of the typical form from Indonesia, I concluded that there are differences that allow consideration of P. tenebricosus nigrosericans as a distinct species [characters of nominotypical male P. tenebricosus in brackets]: apical margin of clypeus weakly rounded to almost truncate [with a sharp median tooth], clypeus flattened or with a weak median depression ( Fig. 3 ) [clypeus longitudinally depressed and with two basal calli ( Fig. 8 )], mandible simple [inner margin of mandible bulging in basal half], second tooth of mandible shorter than adjacent ones [three apical teeth of mandible of same length], gena in lateral view almost as broad as width of eye at ocular sinus and with a rounded but clearly visible angle on posterior margin ( Fig. 4 ) [gena in lateral view 1.5× as broad as width of eye at ocular sinus and with posterior margin regularly rounded ( Fig. 9 )], last flagellomere curved and tapering only at apex ( Fig. 5 ) [last flagellomere straight and tapering from base to apex ( Fig. 10 )], T 1 in lateral view more strongly curved dorsally, mesosoma less densely punctured and propodeum with finer striae. Differences in females are less evident than in males, but can be summarized as follows: more robust species, anterior pronotal carina less elevated and not lamellate [anterior pronotal carina elevated and shortly lamellate], posterior face of propodeum broader than long and with a broad shallow depression ( Fig. 6 ) [posterior face of propodeum as long as broad and with a narrower and deeper depression ( Fig. 11 )], T 1 in dorsal view as long as broad or broader than long [T1 longer than broad], T 1 in lateral view strongly curved dorsally [T 1 in lateral view weakly curved dorsally], dorsal plate of metapleura transversely striate [dorsal plate of metapleura punctate], clypeus and gena more coarsely punctured. Wings orange-yellow with orange venation [wings fuscous-hyaline with black-brown venation].

Figures

FIGURES 1–4. Polistes (Gyrostoma) nigrosericans Bequaert, 1940. 1, 3–4, ♂. 2, ♀. 1–2, Habitus. 3, Head in frontal view. 4, Head in lateral view.

FIGURES 5–6. Polistes (Gyrostoma) nigrosericans Bequaert, 1940. 5, ♂. 6, ♀. 5, Apex of antenna in lateral view. 6, Propodeum in postero-dorsal view.

FIGURES 7–11. Polistes (Gyrostoma) tenebricosus Lepeletier, 1836. 7, 11, ♀. 8–10, ♂. 7, subspecies leopoldi Bequaert, 1940. 8–11, typical form. 7, Habitus. 8, Head in frontal view. 9, Head in lateral view. 10, Apex of antenna in lateral view. 11, Propodeum in postero-dorsal view.