Picnoseus laevigatus Denier, 1935

(Fig. 53)

Picnoseus laevigatus Denier, 1935: 165; Blackwelder 1945: 487 (cat.).

Type Material. After several searches in the museum collections, we have not been able to find the type specimen. Probably lost or destroyed. However, we studied voucher specimens deposited at (MLPC), identified by the specialist Denier, and specimens deposited at (LEC), (JEBTC), (IADIZA) and (MZLU) collections. The characters match those of the original description, except for the size differences.

Material examined. Chile, Carretera: Algarrobal, III Región, I/ X/1987, Col. J. E. Barriga-Tuñón, 1 ♂ LEC. Chile, Algarrobal: Huasco, 11/IX/84, Col. J. E. Barriga-Tuñón, 4 ♂ LEC. Chile, Castilla: Copiapó, 13/IX/84, Col. J. E. Barriga-Tuñón 1 ♀ LEC. Chile: Caldera 15/IX/84, Copiapó, Col. J. E. Barriga-Tuñón, 2 ♂ LEC. Chile: Algarrobal, J. E Barriga, 01/X/1987, 2 ♀ JEBTC and 1 ♀ LEC. Chile: Huasco, Coll. J. E Barriga, 01/X/1987, 1 ♀ LEC. Chile, [Copiapó: Minas, Santa Dominga, Coll. Sergio Roig, X / XI/1992, 3 ♀ IADIZA. Chile, Melipilla, Laguna Esmeralda, Coll. F. Ramírez, 26-X-2010, 1 ♀ JEBTC. Chile, Huasco Algarrobal, 15/IX/1984 Leg. J. E. Barriga, Coll. J. E. Barrigal, 1 ♀ JEBTC. Chile, Copiapó: Playa Totoralillo, Coll. Sergio Roig, X‒1992, 1 ex IADIZA. Chile, Copiapó, prov. W. Copiapó, 3/XII/1999, leg. J. E. Barriga, Picnoseus laevigatus, Denier, MZLU-COL: 00008237.

Other material examined. Chile, Algarrobal: Huasco, 11/IX/84, Col. J. E. Barriga, 1 ex LEC. Chile, Copiapó, Caldera 15 sep. 1984, Leg. J. E. Barriga, Coll. J. E. Barriga, 2 exx JEBTC. Chile, Huasco: Algarrobal, 26/XI/1984, Leg. J. E. Barriga, Coll. J. E. Barriga, 1 ex JEBTC. Chile: Elqui, 5km SW Charos Bajos, 14 oct. 2005, Leg. J. E. Barriga, 6 exx JEBTC. Chile, Copiapó: Minas Sta. Dominga, X/1992 S. Roig, 3 exx IADIZA. Chile Copiapó: Playa Totoralillo, X/1992 S. Roig, 1 ex IADIZA. Chile, Copiapó: Caldera, X/1992 S. Roig, 1 ex IADIZA. Chile, II Región, Chañaral Calera, X/1992 S. Roig, 3 exx IADIZA.

Diagnosis. Elytra black with yellow irregular spot at anterior one-third that continued as a wide marginal vittae towards the apex. Head and pronotum surface covered with medium, shallow, and dense punctures. Setation black or brown; short and erect dorsally; elongate ventrally. Antennomere I proximally narrowed, broadest distally; antennomere II cup-shaped; antennomere III progressively divergent from base to apex; antennomeres IV – VII smoothly divergent distally; antennomeres VIII–X parallel-sided (apex and base of equal width). Profemur with the same length than protibia, mesofemur and metafemur shorter than mesotibiae and metatibiae. Elytra with total length 5.5 mm; with sinuous sides (maximum width at posterior two-third); suture dehiscent apically. Hindwings with reduced venation, see table 2a. Male genitalia with spiculum gastrale with four acute spiniform projections joined by a concavity; median concavity broad and U-shaped, narrowing proximally and becoming slightly curved to the right; aedeagus with two hooks (Fig. 40).

Redescription. Small- medium sized species; length 9–12 mm.

Coloration. Head, pronotum, and abdomen black, dark- brown or brown; lustrous tegument. Antennae, mouthparts and legs dark- brown, reddish or brown. Clypeus dark- brown or brown. Elytra black or dark- brown with yellow irregular spot at anterior one-third that continued as a wide marginal vittae towards the apex. Scutellum black, or pale- brown with dark-brown on margins; lustrous tegument.

Tegument. Head and pronotum surface covered with medium, shallow, and dense punctures. Head integument between punctures micro- reticulate. Pronotum integument between punctures micro- reticulate or slightly rugose. Clypeus punctures similar to those on frons, almost absent in its distal third, which is membranous and glabrous. Labrum punctures smaller than those on clypeus. Elytra without longitudinal visible costae on disk. Scutellum with puncture similar to those on pronotum.

Setation. Black or brown; short and erect dorsally; elongate ventrally. Clypeus and labrum with very sparse setae, thinner than those on head. Protibia with ventral surface (that opposing femur) with an extensive patch of subappressed, transversely directed silky pubescence at distally two-third. Ventral pads of protarsus are evenly distributed throughout its length.

Head. Suborbicular (length 1.5 mm, 1.7 mm; maximum width just above eyes); surface with a longitudinal subtle median groove from the vertex to the fronto-clypeal suture. Temple subparallel, rounded posteriorly. Frons transversely depressed before clypeal suture or with a suborbicular depression on frons (between eyes before clypeal suture). Eyes swollen; anteriorly slightly emarginated in front of antenal insertion; ventral lobe abruptly narrowing below (wide 0.6 mm; long 0.9 mm). Clypeus transverse, slightly bulged (wide 0.5 mm; long 1 mm). Labrum surface with a median depression; lateral edge moderately rounded, their surface smoothly curved inward; ventral edge concave (wide 0.5 mm; long 1.1 mm). Maxillary palpomere IV subrectangular, widest at distal two-third, proximally narrowed; distally with a slight anterodorsal curvature (difficult to see). Labial palpomere subquadrate (with the same width on both extreme). Mandible short, markedly curved on the external sides, covered by clypeus and labrum while resting. Antennae loosely articulated (Fig. 15). Antennomere I proximally narrowed, broadest distally; antennomere II cup-shaped; antennomere III progressively divergent from base to apex; antennomeres IV – VII smoothly divergent distally; antennomeres VIII–X parallel-sided (apex and base of equal width). Antennomeres length: male: I 0.25 mm; II 0.1 mm; III 0.4 mm; IV 0.30 mm; V 0.25 mm; VI 0.27 mm; VII 0.30 mm; VIII–X 0.37 mm; XI 0.5 mm. Female: I 0.37 mm; II 0.10 mm; III 0.25 mm; IV – VI 0.30; VII 0.46 mm; VIII‒X 0.49; XI 0.73 mm.

Pronotum. Suborbicular (long 1.8 mm; wide 2 mm); maximum width at apical third, with angulous borders; surface with two suborbicular depressions on the posterior third and one suborbicular depression at the middle of the basal edge.

Legs. Profemur with the same length than protibia (2.6 mm; 2.5 mm respectively); mesofemur and metafemur shorter than mesotibiae and metatibiae (2.9 mm, 3.3 mm and 3.6 mm, 4.1 mm respectively). Metatibiae spurs dissimilar, inner spur broad expanded, rotated inwards, outer spur obliquely truncate; not parallel but divergent, forming an angle of 20 degrees. Tarsomere measurement: foretarsomere (I 0.49 mm; II and III 0.39; IV 0.23 mm; V 0.66 mm); mesotarsomere (I 0.99 mm; II 0.49 mm; III and IV 0.39 mm; and V 0.66 mm); and metatarsomere (I 1.3 mm; II 0. 66 mm; III 0.49 mm; and IV 0.89 mm).

Elytra. Total length 5.5 mm; with sinuous sides (maximum width at posterior two-third); suture dehiscent apically.

Hindwings with reduced venation, see table 2a (Fig. 24).

Male genitalia (Fig. 40). SpGs with four acute spiniform projections joined by a concavity; median concavity broad and U-shaped, narrowing proximally and becoming slightly curved to the right. Pa distally with elongate apical setae; surface incompletely sclerotized, each lobe with an extensive membranous area except for a Y shaped sclerotized region. This region consists of a narrow median strip that diverges distally and runs along the ventromedial surface of each lobe. Ph with a medial U -shaped concavity; Pa and Ph fused ventrally by a marginal sclerotized band. Ae distally with two hooks: one DAH and one robust VAH. AeA short and slightly curved.

Female genitalia. Sclerotized pale of Va subtriangular, external border with proximal spine, internal border with two spines; proximally elongate and straight BsVa; suborbicular Sty as lon as Va.

Intraspecific variations. Variation occurs in the body length: small- medium sized species (length: 9–12 mm); tegument coloration: head, pronotum, and abdomen varying from black to dark- brown or brown, always lustrous; and the elytra macula and vittae varying from black to dark- brown.

Geographic Distribution. Picnoseus laevigatus presents a wide area of distribution occurring in Monte biogeogeographic province in Argentina; and Santiago, Coquimbo and Atacama biogeographic provinces in Chile (Fig. 69). Habitat in all these biogeographic provinces are arid.

Natural History. According to specimen labels and the information obtained from iNaturalist platform P. laevigatus was observed in September, October and November visiting flowers of Cristaria sp. (Malvaceae) eating pollen (Available from https://www.inaturalist.org/observations/55749121; date of access April 2025) and on flowers of Nolana spp. (Solanaceae) (Available from https://www.inaturalist.org/observations/135990404; date of access April 2025).