Rileya priscillae Perioto and Lara, 2020

Perioto, Nelson Wanderley, Lara, Rogéria Inês Rosa & Cid Maia, Valéria, 2020, A new species of Rileya Ashmead (Hymenoptera: Eurytomidae) from Brazil associated with Zalepidota Rübsaamen (Diptera: Cecidomyiidae), Revista Chilena de Entomología (Rev. Chil. Entomol.) 46 (1), pp. 97-103 : 99-102

Rileya priscillae Perioto and Lara sp. nov.

( Figs. 1-15 )

Type material. Holotype ♀ [MZUSP] labeled “ BRAZIL, SP, Luiz Antônio \ Estação Ecológica de Jataí \ 21°37’25.3”S / 47°48’25.4”W \ riparian forest \ 12 / II / 2009 \ NW Perioto and team, legs.”; “ex. Zalepidota sp. ( Diptera , \ Cecidomyiidae ) gall in an \ unidentified plant”; “HOLOTYPE \ Rileya \ priscillae sp. n. \ Perioto & Lara” . Paratypes: same data as holotype, 8 ♀♀ and 1 ♂ [ MZUSP] , 6 ♀♀ [ LRRP, # 19341-19346] . The holotype and paratypes examined are in good condition; holotype left wings mounted between coverslips. Additional specimens: same data as holotype, 3 ♀ and 1 ♂ [dissected to scanning electron microscopy, LRRP, #19947].

Etymology. This species is named after Priscilla Yoshi Serapião Hashimoto, cousin of the first author.

Diagnosis. Related to R. hegeli Girault,1916 and R. pallidipes (Ashmead, 1894) , from which it can be separated as follow: forewing with stigma not enlarged and Gt 3 asetose (vs. forewing with stigma swollen, circular or ovate and Gt 3 with short, transverse row of 2-4 setae subdorsally as in R. hegeli ); head subtriangular, postorbital carina present, midlobe of mesoscutum about 0.8× as long as broad and color reddish brown with blackish brown areas on head, dorsum of propodeum, mesoscutum, axillae and, Gt 1-3 and Gt 4-6 (vs. head subovate, postorbital carina absent, midlobe of mesoscutum about 1.3× as long as broad and color light to dark brown as in R. pallidipes ).

Description. Holotype female ( Figs. 1-2 ). Body length 2.8 mm. Color: mainly body reddish brown except by: blackish brown on head, dorsum of propodeum, 2/3 anterior of mesoscutum, axillae, dorsal central portion Gt 1-3 and Gt 4-6; golden on: legs, tegula and scape. Wing hyaline, venation light brown. Head: subtriangular in frontal view, with few striae radiating from clypeus toward lower eye margin, face and frons with interstices finely reticulate ( Fig. 3 ). Clypeus bilobate ( Fig. 4 ); supraclypeal area at same level of remainder of face. Malar space 0.5× eye height, postorbital carina present ( Fig. 5 ). Eye glabrous. Scrobal depression deep, margined ( Fig. 3 ). Antenna ( Fig. 6 ): scape 4.0× as long as broad, broadest basally; anelli transverse, A 1-3 shorter than long; F1 1.2×, F2 1.0×, F3-4 0.9×, F5 0.8× as long as broad; clava 1.8× as long as broad, segmented, tapering apically. Mesosoma ( Figs. 7-8 ): foveate reticulate. Midlobe of mesoscutum 0.8× as long as broad, notaulus complete, posteriorly faint. Mesoscutellum as long as broad, crudely carinate apically; lateral panel of axilla sparsely setose, imbricate. Mesepisternum and mesepimeron granulate with transverse and coarse striae. Propodeum carinate, with median panel granulate between carinae; median carina present in the posterior third; primary costula transversely oriented, incomplete medially, turning to intercept dorsellum submedially; four complete carinae connecting the primary costula to nucha; secondary costula absent; spiracle obliquely oriented, reniform, ~1.0× its length from dorsellum ( Fig. 9 ). Forewing ( Fig. 10 ) 2.4× as long as broad, stigma not enlarged and 0.4× as long as stigmal vein, marginal vein 1.1× as long as postmarginal vein, completely setose. Metasoma ( Figs. 11-12 ). Petiole barely visible in dorsal view, transverse. Gaster not laterally flattened. Gt 1-2 smooth, 2/3 basal of Gt 3 imbricated, with sculpturation becoming faint toward the apical margin, remaining terga reticulate; Gt 1–3 glabrate, foreshortened; Gt 1 2.0× as long as Gt 2 and 1.3× as long as Gt 3, Gt 1-3 0.6 as long as Gt 4; Gt 1-3 glabrate, Gt 4-7+8 setose; Gt 5 not emarginate to expose Gt6 spiracle; Gt 7+8 triangular in dorsal view. Variation: body length 2.8-2.9 mm. Malar space 0.5-0.6× eye height. Scape 3.9-4.0× as long as broad, F1 1.1-1.3×, F2 0.9-1.1×, F3-4 0.9-1.1×, clava 1.8-2.1× as long as broad. Midlobe of mesoscutum 0.7-0.8× as long as broad. Mesoscutellum 1.0-1.1× as long as broad. Stigma 0.4-0.5× as long as stigmal vein, marginal vein 1.0-1.2× as long as postmarginal vein. Gt 1 2.0-2.5× as long as Gt 2 and 1.2-1.3× as long as Gt 3, Gt 1-3 0.6-0.7× as long as Gt 4.

Male ( Figs.13-15 ). Length 2.5-2.8 mm. Very similar to female, except as follows: F1 1.3-1.5×, F2 1.0-1.2×, F3-4 1.1×, F5 1.0× and, clava 2.7-2.9× as long as broad; petiole visible in dorsal view, 0.9-1.0× as long as broad, granulate and longitudinally rugose ( Fig. 15 ). Gt 5 distinctly emarginate to expose Gt 6 spiracle, Gt 7+8 hemispherical in posterior view.

Species identification. In the key provided by Gates (2008) this species runs to couplet 32’ and can be separated by an additional couplet as follows:

32’(31). Gt 3 asetose. Forewing with stigma never enlarged.

- Color light to dark brown [some females with darker dorsal spot on gaster, Fig. 251 in Gates, 2008]. Head subovate. Postorbital carina absent. Midlobe of mesoscutum about 1.3× as long as broad …..................................................................... Rileya pallidipes (Ashmead, 1894)

- Color mainly reddish brown, blackish brown on head, dorsum of propodeum, anterior two-thirds of mesoscutum, axillae, dorsal central portion of Gt 1-3 and Gt 4-6 ( Figs. 1-2 , 13 ). Head subtriangular ( Fig. 3 ). Postorbital carina present ( Fig. 5 ). Midlobe of mesoscutum about 0.8× as long as broad ( Fig. 8 ) ...................…… Rileya priscillae Perioto and Lara sp. nov.

Distribution. BRAZIL, São Paulo state (new record).

Biology. Reared from galls of Zalepidota sp. ( Diptera : Cecidomyiidae ) in an unidentified plant species.

Comments. The genus Zalepidota is, for the first time, confirmed as a host of Rileya . Rileya is, for the first time, reported to state of São Paulo, Brazil.

Figures

Figures 1-6. Rileya priscillae Perioto and Lara sp. nov., female. 1. Habitus, lateral. 2. Habitus, latero dorsal. 3. Head, frontal. 4. Clypeus and mandibles. 5. Head, lateral. 6. Antenna.

Figures 7-12. Rileya priscillae Perioto and Lara sp. nov., female. 7. Mesosoma, lateral. 8. Mesosoma, dorsal. 9. Propodeum, dorsal. 10. Fore wing. 11. Metasoma, lateral. 12. Metasoma, dorsal.

Figures 13-15. Rileya priscillae Perioto and Lara sp. nov., male. 13. Habitus, latero dorsal. 14. Habitus, dorsal. 15. Petiole, dorsal.