Horismenus atlanticus Pikart, 2024

Pikart, Tiago G., Schoeninger, Karine, Costa, Valmir A., Hansson, Christer, Zanuncio, José C. & Serrão, José E., 2024, Nine new species of Horismenus Walker (Hymenoptera: Eulophidae) in Brazil, with an emphasis on the fauna of one of the largest tropical forests on the planet, the Atlantic Forest, Zootaxa 5453 (1), pp. 33-62 : 38-41

Horismenus atlanticus Pikart , Costa & Hansson, sp. nov.

Figs 12–20

Type material. Holotype ♀ point mounted, with label “ BRASIL, PR [Paraná], Morretes, Pq. Estadual Pau Oco, 25º34’27,5”S 48º53’33,0”W, Varredura veg.—Am. 4, 09.iv.2002, MT Tavares e eq., col.” (deposited in MZUSP). Paratype. 1♀, “ BRASIL, SP [São Paulo], Ubatuba, Parque Est. da Serra do Mar , 23º01’55”S 44º51’01”W, Varredura Veg. Am. #2, 21.i.2002, N.W. Perioto e eq. col.” (deposited in MZUSP).

Type condition. Holotype complete, in good condition. Paratype without right fore wing, hind legs (except coxae) and gastral tergites, only sternites 1 and 2 present.

Diagnosis. Vertex smooth and shiny, with median groove reticulated ( Fig. 17 ); mesoscutum with strong raised reticulation, midlobe with posterior third with engraved reticulation ( Fig. 19 ); propodeal callus with 2 setae; coxae metallic dark ( Fig. 12 ); costal cell bare; petiole 2.9x as long as wide; first gastral tergite smooth and shiny ( Fig. 20 ). Similar to Horismenus leius Hansson , but interscrobal and clypeal surface metallic blue ( Fig. 14 ), interscrobal area adjacent to frontofacial sulcus narrowest ( Fig. 15 ), upper frons with strong raised reticulation, median groove on vertex reticulate ( Fig. 17 ), posterior ocellus closer to eye than to occipital margin, petiole longer.

Description. Female. Length of body 2.0 mm.

Color. Scape yellowish brown, pedicel brown with metallic tinges, flagellum brown with metallic tinges gradually changing to light brown in the last flagellomere ( Fig. 12 ). Frons dark brown with metallic blue tinges on smooth parts ( Fig. 14 ). Vertex dark brown on reticulated parts and metallic golden green to metallic bluish green on smooth parts. Mesoscutum and mesoscutellum dark brown with metallic golden green to metallic bluish green parts ( Fig. 13 ). Propodeum dark brown on reticulated parts and metallic golden green to metallic bluish green on smooth parts ( Fig. 13 ). Coxae dark brown with metallic tinges with apical part light brown to entirely brown with metallic tinges; femora, tibiae, and tarsi yellowish brown ( Fig. 12 ). Wings hyaline. Petiole dark brown. Gaster with first tergite dark brown in posterior one-third and metallic bluish green in anterior two-thirds, remaining tergites metallic dark brown.

Head. Antennae as in Fig. 16 . Frons ( Fig. 15 ) with clypeal area smooth and shiny, interscrobal surface and part just above frontofacial sulcus with weak raised reticulation, lower frons with strong raised reticulation medially; frontofacial sulcus V-shaped, incomplete and not reaching eyes; antennal scrobes joining frontofacial sulcus separately. Malar sulcus present. Vertex smooth and shiny; median groove present like a reticulated row extending to the anterior ocellus ( Fig. 17 ). Occipital margin rounded with reticulation.

Mesosoma. Mesoscutum with lateral lobes and anterior two-thirds of midlobe with strong raised reticulation, posterior one-third of midlobe with strong engraved reticulation; notauli distinct as narrow grooves on anterior half. Mesoscutellum smooth and shiny laterally with wide mesh-rows; median groove not reaching posterior margin of scutellum. Metascutellum convex, smooth, and shiny with a large fovea along anterior margin. Propodeum ( Fig. 18 ) smooth and shiny, including anterior one-quarter of submedian grooves, posterior three-quarters of the submedian grooves, nucha, supracoxal flange and plicae with strong raised reticulation, median carina with longitudinal striae or with strong raised reticulation, anterolateral foveae large, reaching plicae ( Fig. 18 ); propodeal callus with 2 setae. Coxae smooth and shiny. Fore wing with speculum closed posteriorly, with 18 admarginal setae; costal cell bare.

Metasoma. Gaster rounded ( Fig. 20 ), with first tergite smooth and shiny with a reticulate band near posterior margin, weakened medially, not apparent on SEM images.

Ratios. DE/DO 5.8; WH/DE 2.0; HE/MS/WM 2.5/1.0/1.6; POL/OOL/POO 3.2/1.2/1.0; WH/WT 0.9; LW/LM/ HW 1.8/1.1/1.0; PM/ST 1.0; LC/WC 4.0; WG/WC 1.5; LS/LT 0.2; LP/WP 0.8; MM/LG 0.9.

Male. Unknown.

Etymology. The specific name given in reference to the biome where the species was collected, Atlantic Forest.

Distribution. Brazil (Paraná and São Paulo States).

Hosts. Unknown.

Species identification. Using the key in Hansson (2009), females run to subkey C, couplet 8, first alternative, where this species can be differentiated from H. leius by the characteristics mentioned above in the diagnosis.

Figures

FIGURES 12–14. Horismenus atlanticus sp. nov., female, holotype: 12, habitus, lateral view; 13, mesosoma, dorsal view; 14, head, frontal view. Scale bar: 12 = 500 μm; 13–14 = 100 μm.

FIGURES 15–20. Horismenus atlanticus sp. nov., female, holotype: 15, head, frontal view; 16, antenna, lateral view; 17, vertex, with median groove indicated by yellow arrow; 18, propodeum with wide anterolateral foveae reaching plicae (black arrows); 19, mesosoma, dorsal view; 20, gaster, dorsal view. Scale bar: 15–17, 19–20 = 100 μm; 18 = 50 μm.