Horismenus pterathrix 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 : 52-54

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

Figs 61–71

Type material. Holotype ♀ point mounted, with label “ BRASIL, ES [Espírito Santo], Santa Teresa, Est [ação] Biol [ógica] Sta [ Santa ] Lúcia , 19º58’25,2”S 40º31’44.6”W, Varredura veg.—Am. 19, 7.iv.2001, CO Azevedo e eq., col.” (deposited in MZUSP) . Paratype. 1♀, with the same label data as the holotype, except Am. 1 and 8.iv.2001 (deposited in MZUSP) .

Type condition. Holotype without left fore leg, right fore wing and left hind wing, and hind leg missing left femur, tibia, and tarsus; head glued separately on the point. Paratype missing right antenna and left flagellum and pedicel, left fore and right hind wings. Both holotype and paratype with gaster telescoped.

Diagnosis. Vertex hairy ( Fig. 68 ); mesoscutum with strong raised reticulation ( Fig. 70 ); mesoscutellum smooth and shiny ( Fig. 70 ); fore wing densely hairy ( Fig. 64 ), with speculum small and with an incomplete row of setae on ventral surface of costal cell ( Fig. 65 ); 15–17 setae on propodeal callus and supracoxal flange. Similar to Horismenus capillatus Hansson , but with vertex entirely smooth ( Fig. 68 ), mesoscutellum with median groove distinct ( Fig. 70 ), propodeum metallic golden green ( Fig. 63 ), metascutellum with two large foveae ( Fig. 69 ), and propodeal callus with more setae.

Description. Female. Length of body 1.5 mm (approximate value, due to the gaster telescoped).

Color. Scape yellowish brown to pale brown ( Fig. 61 ), pedicel and flagellum pale brown to brown with metallic tinges. Frons and vertex dark brown with metallic tinges ( Fig. 62 ). Mesoscutum and mesoscutellum dark brown with metallic tinges ( Fig. 63 ). Propodeum dark brown with metallic golden green tinges ( Fig. 63 ). Coxae brown to dark brown with a metallic tinge; femora pale brown, tibiae, and tarsi yellowish to yellowish white ( Fig. 61 ). Wings hyaline. Petiole dark brown. Gaster with first tergite brown to dark brown with metallic bluish green tinges in anterior half, following tergites dark brown.

Head. Antennae as in Fig. 67 . Frons with area below antennal scrobes and posterior half with strong raised reticulation, remaining parts smooth and shiny ( Fig. 66 ); frontofacial sulcus V-shaped, incomplete, and not reaching eyes; antennal scrobes joining frontofacial sulcus separately. Vertex ( Fig. 68 ) smooth and shiny, with many long setae; median groove absent. Occipital margin with a rounded edge behind ocellar triangle.

Mesosoma. Mesoscutum ( Fig. 70 ) with strong raised reticulation, weakening near posterior margin; notauli present as indistinct triangular depressions, forming the posterior half of the midlobe into a triangle. Mesoscutellum ( Fig. 70 ) smooth and shiny; median groove not reaching to posterior margin, covering about two-thirds of the length of mesoscutellum. Metascutellum ( Fig. 69 ) convex, smooth, and shiny, anteriorly with two large foveae. Propodeum including submedian grooves ( Fig. 69 ) smooth and shiny; anterolateral foveae wide; 15–17 setae distributed on propodeal callus and supracoxal flange. Fore wing with small speculum that is closed posteriorly ( Fig. 64 ); with approximately 20 admarginal setae [actual number difficult to count due to the dense pilosity on the fore wing]; costal cell with an incomplete row of setae on ventral surface ( Fig. 65 ).

Metasoma. Gaster collapsed; first tergite smooth and shiny with sparse setae laterally; fringe of setae on the posterior margin of the gaster apparent due to its collapse (see Fig. 71 ). Outer plate of ovipositor (OPO) with reticulated lateral depressions and with a tuft of setae.

Ratios. DE/DO 5.4; WH/DE 2.0; HE/MS/WM 2.5/1.0/1.4; POL/OOL/POO 2.8/1.1/1.0; WH/WT 1.0; LW/LM/ HW 1.0/1.0/1.4; PM/ST 0.6; LC/WC 2.1; WG/WC 0.3; LS/LT 0.3; LP/WP 1.2; MM/LG not measurable, due to the telescoped gaster.

Male. Unknown.

Remarks. The material examined has a certain weak metallic bluish tinge in parts such as the frons, vertex and pronotal collar, depending on the lighting used. Storage in alcohol for a long period after collection may have altered the color of the specimens.

Etymology. The specific name is from the Greek ptera = wing, and thrix = hair, in reference to hairy wings in female.

Distribution. Brazil (Santa Teresa, Espírito Santo State).

Hosts. Unknown.

Species identification. Using the key in Hansson (2009), females run to subkey J, couplet 1, where the second alternative leads to couplet 13, which is modified as:

13a. Propodeal callus with 15–17 setae.............................................. Horismenus pterathrix sp. nov.

- Propodeal callus with less than 10 setae.................................................................. 13

Figures

FIGURES 61–65. Horismenus pterathrix sp. nov., female, paratype: 61, habitus, lateral view; 62, head, frontal view; 63, mesosoma, dorsal view; 64, fore wing; 65, base of fore wing, setae on costal cell indicated by black circles and speculum by dashed circle. MV = marginal vein; SM = submarginal vein. Scale bar: 61 = 500 μm; 62–63 = 100 μm; 64 = 200 μm; 65 = 50 μm.

FIGURES 66–71. Horismenus pterathrix sp. nov., females:66, head, frontal view, holotype; 67, antenna, lateral view, holotype; 68, vertex, paratype; 69, propodeum, holotype; 70, mesosoma, dorsal view, holotype; 71, gaster, dorsal view, holotype. Scale bar: 66, 68, 70–71 = 100 μm; 67, 69 = 50 μm.