Liphanthus (Liphanthus) nigriceps, Vivallo, Felipe, 2008

Vivallo, Felipe, 2008, Liphanthus Reed, 1894 (Hymenoptera, Andrenidae, Protandrenini): Two new Argentine species and keys to the species of the subgenera Liphanthus s. str. and Melaliphanthus Ruz & Toro, 1983, Zootaxa 1854, pp. 55-62 : 58-60

Liphanthus (Liphanthus) nigriceps new species

( Figs. 5–8 )

Comments. Following the key given by Ruz & Toro (1983) for the species of Liphanthus , this new species belongs to the subgenus Liphanthus s. str. The male of this new species is similar to L. barbatus in the laterodistal margin of the clypeus in frontal view strongly concave, but differing from it by the unmodified flagellum (not enlarged distally), the convex distal margin of the labrum, the absence of the yellow band of T1 (one paratype with two small yellow spots), the spine-like projections in the hind tibia, the dark brown coloration of labrum, as well as the larger size of the yellow spot on clypeus.

On the other hand, the female has the paraocular area uniformly black, which disagrees with the diagnosis given by Ruz & Toro (1983) for females of the subgenus Liphanthus s. str. to which this new species belongs. The morphological characters of this female prevents the use of the key of Ruz & Toro for Liphanthus s. str. (couplets 41 to 43 in Ruz & Toro, op. cit.), because both options of the first couplet are present. Morphologically, the female is similar to L. sabulosus Reed , in exhibiting the second submarginal cell with anterior margin about as long as posterior, although the length of the marginal cell is less than the distance between its apex to the wing tip (second option of couplet 41 in Ruz & Toro, op. cit.). The facial fovea is widened ventrally as in L. brevicornis Ruz & Toro , although the metasoma is strongly areolate (second option of couplet 42 in Ruz & Toro, op. cit.). The facial fovea is subparallel to the ocular orbits as in L. barbatus Ruz & Toro , although the metasoma is red, not black, and the clypeus is more than 3 times wider than long, unlike this species and L. chillanensis Ruz & Toro.

Description. HOLOTYPE MALE: Dimensions: Approximate total length: 5.92; forewing length: 4.01; head length: 1.47; head width: 2.01; facial fovea length: 0.22; facial fovea width: 0.08; labrum width: 0.5; labrum length: 0.36; marginal cell length: 0.88; distance from its apex to the wind tip: 0.98. Coloration: Black, with the following areas yellow: mandibles (apex mahogany), paraocular area, inverted triangular area on disk of clypeus, frons, under side of flagellum (F1 through F8 and F11), pronotal lobe, small spot on tegula, distal margin of trochanters and femora, fore and middle tibiae and tarsi, external surface of hind basitarsus and transverse band on T2. T1, in some specimens, with two yellow spots, not well defined. Veins yellowish brown. Wings hyaline. Pygidial plate mahogany. Punctation: Head with very fine and sparse punctation, very dense between subantennal sutures; clypeus almost smooth, with stronger punctures, denser on the disc. Mesosoma areolate, with relatively dense punctation, except on the dorsal area. Mesocutum with finer and scattered punctation. Metasoma with less coarse and very dense punctation, especially on T1. Distal margin of all terga somewhat substrigulate. Pubescence: Scattered and white, denser in the upper and lateral areas of mesosoma and ventral metasoma. Occiput with long, denser and branched hairs. Clypeus with sparse and scattered pilosity, except on disk. Structure: Head 1.38 times wider than long; facial fovea 2.57 times longer than wide and relatively straight. Labrum 1.4 times wider than long, slightly concave basally (in lateral view) and with apical margin convex. Mandible simple. Outer subantennal sutures curved, converging downwards; inner subantennal sutures almost straight, converging slightly upward. Ocular orbits divergent downward. Marginal cell 0.9 times longer than its apex and wing tip. Hind tibia with posterior margin with spinelike projections on the outher side. Lateral fovea of T2 nearly half the width of tergum. Basitibial plate oval, with elevated edges, in lateral view.

ALLOTYPE FEMALE: Dimensions: Approximate total length: 6.04; forewing length 4.03; head width: 1.87; head length: 1.76; facial fovea length: 0.38; facial fovea width: 0.06; labrum length: 0.34; labrum width: 0.4; marginal cell length: 0.98; distance from its apex to the wing tip: 0.93. Coloration: Black, with the following areas yellow: between the inner and outer subantennal sutures, pronotal lobe and apex of tibia. Mandible mahogany, slightly orange at the base. Flagellum and veins brown. Tegula translucent, with small yellow spot. Metasoma reddish, with T1, T4 and T5 dark brown. Lateral fovea of T2 black. Punctation: Dense and strong on head, denser in the paraocular area, and stronger and more scattered on clypeus. Mesosoma areolate, with dense and sparser punctation on mesoscutum and scutellum. Metasoma with dense and fine punctation, with distal margin of terga somewhat substrigulate. Pubescence: White and long on head, legs and lateral areas of mesosoma. Pronotum, pronotal lobe, metanotum and propodeum with short, thicker and branched hairs. Mesoscutum with yellow, scattered and very short hairs. Dorsal area of metasoma with white and very short hairs, longer on the edge of the distal margin of terga. Tibial scopa with long and simple hairs. Inner surface of hind basitarsus with dense and short pilosity. Structure: Head 0.94 times wider than long, facial fovea 6.67 times longer than wide, subparallel, almost half the length of the eye in frontal view, and widened downward. Labrum 1.18 times wider than long, slightly concave distad. Mandible simple. Subantennal sutures converging downwards. Ocular orbits almost parallel, slightly divergent downward. Marginal cell length 1.05 times the distance between its apex to the wing tip. Basitibial plate oval, with raised edges. Pygidial plate broad, with rounded apex and longitudinal median ridge.

Distribution. Argentina: Mendoza: Las Heras.

Type material. Argentina: Mendoza: Las Heras: Holotype male, ARG. Mendoza 1459m Las Heras 32º31'47.1''s 68º59'24.5''w 10-Octubre-2004 F. Vivallo. Allotype female: ARG Mendoza 1264m Las Heras 32°32’31.3”s 68°57’18.9”w 10-Octubre-2004 F. Vivallo. Paratypes (2 males) with the same date and local of collect than the holotype. The holotype, allotype and one paratype will be deposited in the collection of the Pontificia Universidad Católica de Valparaíso, Chile ( PUCV). One paratype will be deposited in the Museo de Ciencias Naturales “Bernardino Rivadavia” ( MACN), Buenos Aires, Argentina.

Etymology. The specific name derives from the greek “black head”, due to the absence of yellow on the lower paraocular areas in females, present in other species of the subgenus Liphanthus s. str.

Figures

FIGURES 5 – 8. Liphanthus (Liphanthus) nigriceps n. sp. 5, head of male (holotype) in frontal view. 6, male (holotype) in lateral view. 7, head of female (allotype) in frontal view. 8, female (allotype) in lateral view. Scale bar = 1 (mm).