Euxestophaga Gallardo, 2017

Gallardo, Fabiana E., Reche, Vanina Anadina, Bertolaccini, Isabel, Brenda Zarate, & Curis, Cecilia, 2017, A new genus and species of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae) parasitoid of Euxesta eluta Loew (Diptera, Otitidae) attacked Bt sweet corn in Argentina, Journal of Hymenoptera Research 54, pp. 57-70 : 58

Euxestophaga Gallardo gen. n. Figures 1-4

Diagnosis.

This new genus can be separated from other Ganaspini by the following combination of characters: occiput diagonally striate; female antenna clavate, club consisting of six flagellomeres; male antenna with F1 modified and longer than F2; dorsal surface of scutellum areolate-punctate, posterior border of disc bluntly rounded; lateral bars of scutellum striate; dorsal surface of scutellar plate with midpit placed close posterior margin of plate, with two or three punctures on each side, with a setae on either side; forewings hyaline, apical margin with hair fringe, marginal cell closed; base of syntergum with hairy ring present; and micropunctures present on posterior1/3 of the syntergum.

Type species.

Euxestophaga argentinensis Gallardo, sp. n.

Description.

Body stout, shiny. Head massive, subcircular in anterior view, broader than mesosoma, nearly glabrous. Toruli not projecting. Ocellar tubercle not prominent. Ocellar hair patches absent. Compound eyes glabrous. Inner orbital furrows present. Posterior margin of gena distinct, but not carinate. Occiput diagonally striate. Malar spaces smooth, without conical protuberances. Malar sulci present. Female antenna with 13 segments, club consisting of six flagellomeres; male antennae 15 segments, filiform. Shape of dorsal margin of pronotal plate in anterior view broadly truncate, emarginate. Mesoscutum longer than wide, quite arcuate, without median mesoscutal carinae, with rows of punctures in position of notauli, parascutal impressions incomplete. Shape of posterior part of scutellum in dorsal view bluntly rounded. Lateral bars of scutellum striate. Scutellar foveae wider than long, deep and large. Dorsal surface of scutellum areolate-puntate. Scutellar plate suboval, posterior margin rounded, dorsal surface with midpit placed close posterior margin of plate, with punctures on each side, with a setae on either side. Anteroventral cavity of metapleuron subcircular, setose. Forewings of normal size, hyaline, apical margin with hair fringe, basal margin lacking hair fringe, with membrane pubescence mostly reduced hair bases, marginal cell closed, longer than broad. Metasoma sessile; base of syntergum with hairy ring present, remainder of metasoma glabrous. Micropunctures present on posterior 1/3 of the syntergum more or less visible.

Distribution.

Neotropical region: Argentina. According to the biogeography scheme of Morrone (2001, 2014), this distribution belongs to the biogeographic provinces Chacoan and Pampean (Chacoan subregion).

Biology.

Specimens of this new genus and species were reared from Euxesta eluta on Zea mays L. (Bt sweet corn). Bertolaccini et al. (2010) cited Dettmeria Borgmeier ( Eucoilinae , Zaeucoilini ) parasitizing larvae of Euxesta species on Bt sweet corn in Argentina, but, on reviewing the material mentioned in this paper, we concluded that the specimens were misidentified as Dettmeria , which belongs to the new genus and species here described.

Etymology.

In reference to genus of the host, Euxesta and “phagein”, to eat. Gender: feminine.

Remarks.

Within Ganaspini , Euxestophaga is similar in morphology to Epicoela Borgmeier and Striatovertex Schick, Forshage and Nordlander, all of them present occiput diagonally striate, dorsal margin of pronotal plate emarginated, forewing with erect setae on subcostal and membrane with pubescence reduced. Epicoela includes two species known from Neotropical region, whereas Striatovertex is a genus widespread in the New World, with 13 species in total; one species in Australia, and other introduced in Hawaii from North America ( Schick et al. 2011). With reference to their biology, host species of Epicoela are unknown, while representatives of Striatovertex attack dipterous Sarcophagidae , Muscidae and Calliphoridae .

The three genera can be separated by the following characters:

1	Female antenna with F5 or F6 to F11 moniliform, club consisting of 6 or 7 flagellomeres (Figure 5 ). Dorsal surface of scutellar plate with a triangular concave area in anterior part (Figure 6 ). Lateral bars of scutellum smooth	Epicoela Borgmeier
-	Female antenna with F4 or F6 to F11 moniliform, club consisting of 6 or 8 flagellomeres. Dorsal surface of scutellar plate with punctures on each side with setae either one. Lateral bars of scutellum striate	2
2	Female antenna with F4 to F11 moniliform, club consisting of 8 flagellomeres. Scutellar plate posteriorly arched in lateral view (See Figure 1 in Schick et al. 2011). Posterior margin of scutellum rounded (See figure 5 in Schick et al. 2011). Apical margin of forewing lacking hair fringe, membrane with pubescence mostly reduced to punctiform hair bases (See figure 7 in Schick et al. 2011)	Striatovertex Schick, Forshage & Nordlander
-	Female antenna with F6 to F11 moniliform, club consisting of 6 flagellomeres. Scutellar plate straight in lateral view (Figure 1 ). Posterior margin of scutellum bluntly rounded (Figure 4 , see arrow). Apical margin of forewing with hair fringe (Figure 3 , see arrow), membrane with pubescence mostly reduced hair bases	Euxestophaga Gallardo, gen. n.

Figures

Figures 1 - 4. Holotype of Euxestophaga argentinensis Gallardo sp. n. Female. 1 Habitus (lateral view) 2 Head and mesosoma (dorsal view), arrow indicates posterior margin of gena distinct, but not carinata 3 Head (posterior view) and mesosoma (dorsal view), arrow indicates basal margin of forewing lacking hair fringe. Male 4 Antenna, arrow indicates posterior margin of scutellum bluntly rounded.

Figures 5 - 6. Holotype of Epicoela seminigra Diaz Female. 5 Antenna 6 Scutellar plate (dorsal view).