Horismenus parvicavus 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 : 49-50

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

Figs 51–60

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. 29, 8.iv.2001, CO Azevedo e eq., col.” (deposited in MZUSP) . Paratype. 1♀, with the same label data as the holotype (deposited in MZUSP) .

Type condition. Holotype with gaster telescoped. Paratype without left fore wing and gaster telescoped.

Diagnosis. Area below antennal scrobes and malar space with strong raised reticulation ( Fig. 55 ); vertex with strong raised reticulation and median groove absent ( Fig. 57 ); mesoscutellum entirely reticulated, without median groove and lateral mesh-rows ( Fig. 59 ); metascutellum with strong raised reticulation, without anterior foveae ( Fig. 58 ); propodeum with submedian grooves narrowed, WG/WC= 0.1, anterolateral foveae almost completely reduced ( Fig. 58 ) and plicae indistinct; fore wing with 35–36 admarginal setae in two irregular lines ( Fig. 53 ).

Description. Female. Length of body 1.8 mm (approximate value, due to telescoped gaster).

Color. Scape yellowish brown, pedicel, and flagellum pale brown ( Fig. 51 ). Frons and vertex metallic dark brown ( Fig. 52 ). Mesoscutum and mesoscutellum metallic dark brown ( Fig. 54 ). Propodeum metallic dark brown, some parts with metallic blue tinges ( Fig. 54 ). Coxae brown; femora and tibiae yellowish brown; tarsi yellowish white with last tarsomere brown ( Fig. 51 ). Wing hyaline. Petiole dark brown with metallic blue tinges. Gaster metallic dark brown.

Head.Antennae as in Fig. 56 . Frons with interscrobal surface, part just above frontofacial sulcus and just outside the antennal scrobes smooth and shiny, remaining parts with strong raised reticulation ( Fig. 55 ); frontofacial sulcus V-shaped, incomplete, and not reaching eyes; antennal scrobes joining frontofacial sulcus separately. Malar sulcus present. Vertex with strong raised reticulation ( Fig. 57 ); median groove absent. Occipital margin slightly rounded.

Mesosoma. Mesoscutum ( Fig. 59 ) with strong raised reticulations; notauli weakly distinct medially. Mesoscutellum ( Fig. 59 ) with strong raised reticulation; median groove and mesh-rows absent. Metascutellum convex, with strong raised reticulation ( Fig. 58 ); anterior foveae absent. Propodeum ( Fig. 58 ) with weak raised reticulation, with exception propodeal callus and supracoxal flange with strong raised reticulation; submedian grooves narrowed and present in anterior half of propodeum; anterolateral foveae almost completely reduced ( Fig. 58 ) and plicae indistinct; propodeal callus with 3–4 setae. Coxae with weak reticulation. Fore wing with speculum open, posteriorly with 35–36 admarginal setae in two irregular rows ( Fig. 53 ); costal cell bare.

Metasoma. Gaster ( Fig. 60 ) with first tergite with anterior two-thirds smooth and shiny, posterior one-third with weak reticulation.

Ratios. DE/DO 6.0; WH/DE 1.9; HE/MS/WM 2.6/1.0/1.5; POL/OOL/POO 2.9/1.0/1.2; WH/WT 1.0; LW/LM/ HW 1.7/1.0/1.0; PM/ST 1.7; LC/WC 1.8; WG/WC 0.1; LS/LT 0.3; LP/WP 1.4; MM/LG not measurable, due to telescoped gaster.

Male. Unknown.

Remarks. Paratype has pale brown mid coxae.

Etymology. The specific name is from the Latin parvus = small, and cavus = depression, in reference to the small foveae on propodeum.

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

Hosts. Unknown.

Species identification. Specimens can be identified using the key in Hansson (2009) as modified below. Females run to subkey B, couplet 5, where the second alternative leads to couplet 6, which is modified as:

6a. Propodeum with anterolateral foveae almost completely reduced ( Fig. 58 ) and plicae indistinct; metascutellum with strong raised reticulation.......................................................... Horismenus parvicavus sp. nov.

- Propodeum with anterolateral foveae not reduced and plicae distinct ( Fig. 18 in Hansson 2009); metascutellum usually smooth and shiny........................................................................................... 6

Figures

FIGURES 51–54. Horismenus parvicavus sp. nov., female, holotype: 51, habitus, lateral view; 52, head, frontal view; 53, fore wing, admarginal setae indicated by circles; 54, mesosoma, dorsal view. MV = marginal vein; PM = postmarginal vein; ST = stigmal vein. Scale bar: 100 μm.

FIGURES 55–60. Horismenus parvicavus sp. nov., female: 55, head, frontal view, paratype; 56, antenna, lateral view, paratype; 57, vertex, paratype; 58, propodeum with anterolateral foveae greatly reduced (yellow arrow), and metascutellum with strong raised reticulation (white arrow), holotype; 59, mesosoma, dorsal view, notauli distinct only medially, indicated by arrows, holotype; 60, gaster, dorsal view, reticulation in the posterior one-third of the first tergite indicated by arrows, holotype. Scale bar: 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.