JHR 54: 57-70 (2017) ore JOURNAL OF | *0eerrrieved opencoss ural doi: 10.3897/jhr.54. 10096 RESEARCH ARTICLE (ME Hymenoptera http://jhr.pensoft.net The Inerational Society of Hymenoptersts. RESEARCH A new genus and species of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae) parasitoid of Euxesta eluta Loew (Diptera, Otitidae) attacked Bt sweet corn in Argentina Fabiana E. Gallardo!?, Vanina Anadina Reche’, Isabel Bertolaccini?, Brenda Zarate!', Cecilia Curis? | Division Entomologia. Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Paseo del Bosque s/n, BL9OOFWA, La Plata, Argentina 2 Catedra de Zoologia Agricola, Facultad de Ciencias Agrarias, Universidad Nacional del Litoral, R.P Kreder 2805, 3080, Esperanza, Santa Fe, Argentina 3 Researcher of the Comision de Investigaciones Cientificas de la provincia de Buenos Aires (CIC), Argentina Corresponding author: Fabiana E. Gallardo (gallardo@fcnym.unlp.edu.ar) Academic editor: /. Yoder | Received 11 August 2016 | Accepted 20 January 2017 | Published 27 February 2017 http://zoobank.org/OAOBC5 D6-6DB7-4D 76-8 93C-77F27882995C Citation: Gallardo FE, Reche VA, Bertolaccini I, Zarate B, Curis C (2017) A new genus and species of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae) parasitoid of Euxesta eluta Loew (Diptera, Otitidae) attacked Br sweet corn in Argentina. Journal of Hymenoptera Research 54: 57-70. https://doi.org/10.3897/jhr.54. 10096 Abstract Euxestophaga Gallardo, a new genus of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae) and Euxestophaga argentinensis Gallardo, sp. n. from Argentina, are described and illustrated. This new genus belongs to the Ganaspini and morphologically resembles Epicoe/a Borgmeier and Striatovertex Schick, Forshage and Nord- lander. A key to differentiate these genera is given. Specimens were reared from pupae of Euxesta eluta Loew (Diptera: Otitidae), attacked Bt sweet corn in Santa Fe province and other in Tucumén province (Argentina). Keywords New species, cynipoid wasp, natural enemy, Otitidae, Zea mays L. Introduction Eucoiline wasps are koinobiont endoparasitoids of dipterous Muscomorpha larvae and constitutes the most abundant and diverse subfamily of Figitidae. However, there has been poor taxonomic information on this subfamily in the Neotropical region, Copyright Fabiana E. Gallardo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 58 Fabiana E. Gallardo et al. / Journal of Hymenoptera Research 54: 57-70 (2017) the only key to eucoiline genera cited for this region was published by Buffington and Ronquist (2006) and an updated synthesis of the knowledge on this subfamily was given by Diaz et al. (2008). Forshage and Nordlander (2008) proposed a tribal classification recognizing the following taxa: Diglyphosemini, Kleidotomini, Trichop- lastini, Eucoilini and Ganaspini. Later, Buffington (2009) added Zaeucoilini to the group. Species belonging to Ganaspini attack Agromyzidae, Calliphoridae, Canacei- dae, Chloropidae, Drosophilidae, Ephydridae, Lauxaniidae, Lonchaeidae, Phoridae, Sarcophagidae, Sepsidae, Tephritidae and Otitidae. The larvae of Otitidae are gener- ally saprophagous, but some of them have developed phytophagous habits, eg. species of Euxesta Loew (Artigas, 1994). Species of this genus are secondary pests on garlic, tomatoes, potatoes, plants fruits, cassava and sweet corn, among others. Bt sweet corn is a transgenic plant genetically modified to include genes of the naturally occuring soil bacterium Bacillus thuringiensis Berliner (or Bt)”. In Santa Fe province (Argentina), the crops of Bt sweet corn are attacked by spe- cies of Euxesta (Diptera: Otitidae) that are considered secondary pests, causing severe damage to sweet corn. Two species have been identified: EF. mazorca Steycal and E. eluta Loew, both appearing simultaneously and producing serious losses (Bertolac- cini et al., 2010). Larvae attack the silks and consume the kernel contents, especially in the tips, although they can extend to all the ear length. The activity of these larvae constitutes one way of entrance for saprophytic microorganisms, making the product unmarketable for direct consumption. In this context, a new natural enemy of FE. eluta was found, belonging to the tribe Ganaspini. This paper describes the new monotypic genus Euxestophaga Gallardo n. gen., with a new species from Argentina. Methods We studied a total of 72 specimens (46 females and 27 males). The specimens from Santa Fe province were obtained from pupae of Euxesta eluta in the framework of the research project CAI +D 2011: 2011:501 201 101 00009 LI (Universidad Na- cional del Litoral, Argentina). The larvae of Euxesta eluta were collected in a com- mercial crop of sweet Bt corn (hybrid=GSS0974). Each pupa was individually placed in Eppendorf*vials (1.5mm), with a damp paper inside in order to conserve moisture. The pupae were periodically reviewed to determine the emergence of adult flies or par- asitoids. Once the parasitoids emerged, they were preserved in 70% EtOH, together with the host puparia, the adult specimens of the flies host emerging from other non attacked pupae were preserved in 70% EtOH. The terminology used in the description follows Bufhington (2009). Morphological terms used in this revision were matched to the Hymenoptera Anatomy Ontology (HAO, Yoder et al. 2010) (see Appendix). Iden- tifiers (URIs) in the format http://purl.obolibrary.org/obo/HAO_XXXXXXX repre- sent anatomical concepts in HAO version. Biogeographical regions are in accordance with Morrone (2001, 2014). The collection localities were georeferenced with free soft- ware QGIS version 2.10.1- Pisa. The photographs were taken with a Canon Powershot A new genus and species of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae)... 39 A 520 adapted to a Leica steromicroscope (S8APO). Type material is deposited at Mu- seo de La Plata, Argentina (MLP) and United States National Museum (Smithsonian Institution), U.S.A (USNM). Type of Epicoela seminigra Diaz (MLP) and specimens compared to Type of Epicoela rubicunda Borgmeier (MLP) were studied. Results Systematic treatment Euxestophaga Gallardo, gen. n. http://zoobank.org/4AE50295-A5F5-4733-9A3 1-D9426AD831B5 Figures 1-4 Diagnosis. This new genus can be separated from other Ganaspini by the follow- ing combination of characters: occiput diagonally striate; female antenna clavate, club consisting of six flagellomeres; male antenna with Fl 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 posteri- orl/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 fur- rows present. Posterior margin of gena distinct, but not carinate. Occiput diagonally striate. Malar spaces smooth, without conical protuberances. Malar sulci present. Fe- male 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 impres- sions 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 punc- tures 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. 60 Fabiana E. Gallardo et al. / Journal of Hymenoptera Research 54: 57-70 (2017) Distribution. Neotropical region: Argentina. According to the biogeography scheme of Morrone (2001, 2014), this distribution belongs to the biogeographic prov- inces 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 wide- spread 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 Striatover- tex 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... BO ae A ROMO TPT Ci. innerliner ROT EME 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 .............ccccceeseeeseeeeeees 2 2 Female antenna with F4 to F11 moniliform, club consisting of 8 flagellom- eres. 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 Seale 2 OWI ask ee ids Seictat atte Striatovertex Schick, Forshage & Nordlander de Female antenna with F6 to F11 moniliform, club consisting of 6 flagellom- eres. 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 tediced: Wait bases’, nce. svosteneerensescco tenth Euxestophaga Gallardo, gen. n. A new genus and species of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae)... 61 Euxestophaga argentinensis Gallardo, sp. n. http://zoobank.org/70D48C8B-7669-44E5-9F5D-6303CA5A064F Figures 1—4 Material examined. ARGENTINA. Santa Fe. Angel Gallardo. 31°33'18'S; 60°40'36.84"W (DMS). Holotype female (MLP No. 5728/1), 6 paratype females (MLP No. 5728/2-7) reared from Euxesta eluta (Diptera, Otitidae) on Zea mays L.(Bt sweet corn) (Poaceae), 13-VI-2005; 1 paratype female (MLP No. 5728/8) and 1 paratype male (MLP No. 5728/9),10-XII-2010, Bertolaccini and Curis colls. 36 females (MLP No. 5728/10-46) and 24 males (MLP No. 5728/47-61) reared from Euxesta eluta (Diptera, Otitidae) on Zea mays L. (Bt sweet corn) (Poaceae), 02-XII-2015, Bertolaccini coll. (), 1 paratype female (USNM) and 1 paratype male (USNM), same data. Tucuman. 27°0'0"S; 65°30'0"W (DMS), 1 female partype (MLP No. 5728/62), VI-1976, Figalgo coll. San Javier. 26°46'59"S; 65°23'6"W (DMS) 1 male (MLP No. 5728/63), 16-XI- 1981, on herbaceous vegetation, Mulvany, Diaz, Fidalgo and Armesto colls. Description. Female. Total length 1.85-2 mm. (Fig. 1). Head and mesosoma black, metasoma completely dark reddish brown. Antennae brown, mandibles, wings venation and legs yellowish brown. Head (Figs 1-3) in anterior view as high as wide. Malar sulci simple. Antenna (Fig. 1) with 13 segments, pilose, subcylindrical, flagellomeres 1 and 2 subequal in length, F6 to F11 moniliform, club consisting of six flagellomeres, with rhinaria. Pos- terior margin of gena distinct, but not carinata (Fig. 2, see arrow).Pronotum. Pronotal plate (Fig. 2) wide, striate in anterior half as well as bridge that connect this half with posterior half. Posterior half with row of setae, lateral foveae open. Dorsal margin emarginate. Pronotal ridge absent. Sides of pronotum convex, with a pubescent area on upper half of ventral margin (beneath pronotal plate). Mesoscutum. Strongly convex in profile (Fig. 1). Parapsidal ridges represented by hair lines (Figs 2, 3). Parascutal impressions incomplete. Notauli absent. Mesopectus (Fig. 1). Upper part and lower part of mesopleuron smooth, glabrous. Mesopleural carina simple. Precoxal carina present. Subalar pit narrow and shallow. Mesopleural triangle undefined. Surcoxal depression absent. Mesoscutellum. Scutellar foveae (Fig. 3) deep, large, wider than long. Lateral bars of scutellum striate. Dorsal surface of scutellum (Fig. 3) areolate-punctate, posterior margin bluntly rounded. Scutellar plate (Figs 2, 3) suboval, posterior margin rounded, dorsal surface with midpit placed close to posterior margin of plate, with punctures on each side, with single setae in each one. Metapectal-propodeal complex (Fig. 1). Posteroventral corner of metapleuron flat, rounded and pubescent, anteroventral cavity subcircular, setose. Propodeum covered with long, apressed setae. Lateral propodeal carinae semiparalell. Wings. Forewings hyaline (Fig. 1), apical margin with hair fringe, basal margin lacking hair fringe, with membrane pubescence mostly reduced hair bases, marginal cell closed, longer than wide. 62 Fabiana E. Gallardo et al. / Journal of Hymenoptera Research 54: 57-70 (2017) 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. A new genus and species of Eucoilinae (Hymenoptera, Cynipoidea, Figitidae)... 63 Figures 5-6. Holotype of Epicoela seminigra Diaz Female. 5 Antenna 6 Scutellar plate (dorsal view). Legs (Fig. 1). Fore and mid coxa subequal in size, variously setose, hind coxa about twice the size of either fore or mid coxae, with a patch of woolly setae on posterior margin. Femora and tibiae sparsely setose, tibiae with more apprised setae; tarsomeres covered with dense appressed setae. Metasoma (Fig. 1). Base of syntergum with hairy ring completed, remainder of metasoma glabrous. Male. Similar to female. Male antennae (Fig. 4) filiform, 15 segments, Fl curved, longer than following flagellomeres, F2 shorter than other flagellomeres. Metasoma nearly squared posteriorly in lateral view. Metasoma completely dark reddish brown or ventrally yellowish brown. Base of syntergum with hairy ring interrupted apically. Distribution. Argentina. Type locality. Angel Gallardo (Argentina, Santa Fe province). Hosts. Diptera Otitidae: Euxesta eluta Loew. Etymology. In reference to the country where the specimen was collected: Argentina. Acknowledgments We thank Daniel Aquino (MLP) and M. Cecilia Moreno (CIC) for technical support, Nora Cabrera (MLP) for critical review. To George Melika (Plant Protection and Soil Conservation Service of County Vas, Hungary), Juli Pujade-Villar (Universitat de 64 Fabiana E. Gallardo et al. / Journal of Hymenoptera Research 54: 57-70 (2017) Barcelona, Spain), Matthew Bufhngton (Smithsonian Institution, U.S.A) and editors of JHRfor provided many useful suggestions to improve the manuscript. To Comisién de Investigaciones Cientificas de la Provincia de Buenos Aires (CIC), Universidad Nacional de La Plata (UNLP) and Universidad Nacional del Litoral (UNL) for their constant support. References Artigas JN (1994) Entomologia Econdémica. Insectos de interés agricola, forestal, médico y veterinario (Nativos, introducidos y susceptibles de ser introducidos). Vol. 1. Ediciones Universidad de Concepcién, Chile, 1126 pp. Bertolaccini I, Bouzo C, Larsen N, Favaro JC (2010) Especies del género Euxesta (Diptera: Ulidiidae=Otitidae) plagas de maices dulces Bt en la provincia de Santa Fe, Argentina. Revista de la Sociedad Entomoldgica Argentina 69(1—2): 123-126. 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