Gonatocerus virlai S. Triapitsyn, Logarzo

Triapitsyn, Serguei V., Logarzo, Guillermo A., Virla, Eduardo G. & De, Jesse H., 2007, A new species of Gonatocerus (Hymenoptera: Mymaridae) from Argentina, an egg parasitoid of Tapajosa rubromarginata (Hemiptera: Cicadellidae), Zootaxa 1619, pp. 61-68 : 62-67

Gonatocerus virlai S. Triapitsyn, Logarzo & de León sp. n.

( Figs 1–9 )

Gonatocerus sp. 6: Hoddle & Stouthamer 2005: 339; Hoddle & Triapitsyn 2005: 341–342; De León et al. 2006a: 41 –42; De León et al. 2006b: 54; De León et al. 2006c: 57 –58.

Gonatocerus sp.: Jones et al. 2005: 243.

Type material

Holotype female on slide [ MLPA]: ARGENTINA, Tucumán, Tafí Viejo, 7–11.i.2001, E. Virla, “ex. eggs of Tapajosa rubromarginata (Signoret) exposed in citrus fields #F6”. Paratypes: ARGENTINA. CÓRDOBA, Villa de Soto, 30°50’53’’S, 65°00’18’’W, 540 m, 24.i.2003, G. Logarzo, L. Varone (ex. sentinel eggs of T. rubromarginata on citrus left 17.i.2003 by G. Logarzo, L. Varone, E. & M. Virla, W. Jones and S. Triapitsyn, emerged 7.ii. 2003 in UCR quarantine, Riverside, California, USA) [1 male on point, UCRC]. CORRIENTES, Yapeyú, xi.2006, G. Logarzo (ex. eggs of T. rubromarginata ) [1 female, 1 male on points, UCRC]. LA RIOJA: Anillaco, 1–31.iii.2001, P. Fidalgo, J. Torrens, G. Fidalgo [1 female on point, UCRC]. Castro Barros, La Calera, 8.i.2001, P. Fidalgo [1 female on slide, IMLA]. MISIONES, Loreto, 9.xii.1931, A.A. Ogloblin [1 female on slide, MLPA]. SALTA, ca. 14 km N of Rosario de la Frontera, 25°42’45.4’’S, 64°56’10.9’’W, 780 m, 21.i.2003, S. Triapitsyn, G. Logarzo [1 female on point, UCRC]. TUCUMÁN: El Cadillal ([Ruta Nacional] RN9, km 1311), 23.i.1995, E. Virla (ex. eggs of T. rubromarginata on corn) [1 female, 2 males on slides and 1 female, 1 male on cards, CNCI]. San Miguel de Tucumán, soccer field near PROIMI, 26°48’35.6’’S, 65°14’24.6’’W, 500 m, 2002, E. Virla (ex. eggs of T. rubromarginata on Johnson grass) [1 male on slide, UCRC, 2 females on points, IMLA, UCRC, and 12 males on points, IMLA (6), UCRC (3), and USNM (3)]. Tafí Viejo: xii.2000, E. Virla, ex. eggs of T. rubromarginata in citrus orchard [1 female, 1 male on points, UCRC]; 11.i.2001, E. Virla, ex. eggs of T. rubromarginata in field [2 females on points, UCRC]; 7–11.i.2001, E. Virla, ex. eggs of T. rubromarginata in citrus orchard [12 females on points, CNCI (1), IMLA (2), MLPA (2), UCRC (4), USNM (3), 1 male on slide and 1 male on point, UCRC]; 3–10.iii.2002, E. Virla, ex. eggs of T. rubromarginata on lemon (colony originators, emerged en route to USDA, APHIS Mission quarantine laboratory, Edinburg, Texas, USA, died 15–20.iii.2002) [1 female on point, 2 males on slides and 3 males on points, UCRC]. USA. CALIFORNIA, Riverside Co., Riverside, laboratory colony at UCR quarantine: emerged 20.iv.2005 from eggs of H. vitripennis on Euonymus japonica leaves, coll. V. Berezovskiy [1 female, 2 males on points, UCRC]; originally from: Argentina, Tucumán, San Miguel de Tucumán, soccer field near PROIMI, 26°48’35.6’’S, 65°14’24.6’’W, 500 m, 20.i.2003, G. Logarzo, L. Varone, W. Jones, S. Triapitsyn, E. Virla (emerged 10.ii. 2003 in UCR quarantine from eggs of T. rubromarginata on Johnson grass).

Additional material examined

ARGENTINA. CÓRDOBA, Las Tapias, 16–25.i. xi.2003, M. Virla (ex. egg mass of a proconiine sharpshooter on grape leaf) [1 female in alcohol, USDA, ARS SABCL]. CORRIENTES, San Cosme, 11– 13.xi.2003, G. Logarzo, L. Varone (ex. sentinel eggs of T. rubromarginata on citrus) [5 females in alcohol, USDA, ARS SABCL]. LA RIOJA, Anillaco, 7.xi.2002, G. Logarzo, L. Varone (ex. sentinel eggs of T. rubromarginata on citrus) [16 females, 5 males in alcohol, USDA, ARS SABCL]. ENTRE RÍOS, Concordia, 12– 14.xii.2001, G. Logarzo (ex. sentinel eggs of T. rubromarginata on citrus) [2 males in alcohol, USDA, ARS SABCL]. MENDOZA: La Consulta, 23–27.x.2002, G. Logarzo, E. Virla (ex. sentinel eggs of T. rubromarginata on citrus) [2 females, 1 male in alcohol, USDA, ARS SABCL]. San Carlos, i.2007, G. Logarzo, F. Palottini (ex. wild eggs of T. rubromarginata on Populus sp. and from sentinel eggs of T. rubromarginata on citrus) [numerous females and males in alcohol, USDA, ARS SABCL]. MISIONES, Cerro Azul, 27.x.2000, G. Logarzo (ex. sentinel eggs of T. rubromarginata on citrus) [2 females, 2 males in alcohol, USDA, ARS SABCL]. TUCUMÁN: El Manantial, 22–24.i.2005, E. Virla (ex. sentinel eggs of Molomea consolida Schröder on citrus) [3 females in alcohol, USDA, ARS SABCL]. San Miguel de Tucumán, soccer field near PROIMI, 26°48’35.6’’S, 65°14’24.6’’W, 500 m, 21–22.i.2005, E. Virla (ex. sentinel eggs of Molomea consolida Schröder on citrus) [7 females, 1 male in alcohol, USDA, ARS SABCL]. USA. TEXAS, Hidalgo Co., Edinburg, USDA, APHIS Mission quarantine, from laboratory colony (various dates during 2002) [numerous females and males on points, in gelatin capsules, and in alcohol, UCRC]; originally from: Argentina, Tucumán, Tafí Viejo, 3–10.iii.2002, E. Virla (ex. eggs of T. rubromarginata on lemon).

Description

FEMALE (holotype and paratypes). Body length 1.1–1.4 mm. Head, mesosoma, and metasoma ( Fig. 3 ) mostly light brown except trabeculae and vertex (between the ocelli only) dark brown, mesoscutum (posteriorly) and scutellum (anteriorly) with irregular brownish spots, and middle gastral terga brown; scape and pedicel light brown, flagellum brown to dark brown; legs light brown.

Antenna ( Fig. 1 ) with radicle 2.4–2.5 x as long as wide, rest of scape about 3.5 x as long as wide, with strong setae; pedicel longer than F1, with a few strong setae; all funicular segments longer than wide and densely setose (setae short); F2 much longer than F1 and slightly shorter than F3 (F3 and F4 equal in length and the longest funicular segments), F5 a little longer than F6, F7 slightly longer than F6 and notably longer than F8; F1 without longitudinal sensilla, longitudinal sensilla on F2 (0 or 1), F3 (1 or 2), F4 (2), F5 (2), F6 (2), F7 (2), and F8 (2); clava with 8 longitudinal sensilla, 3.2–4.2 x as long as wide.

Mesosoma as in Fig. 5 . Pronotum divided medially, each lobe with 2 strong dorsal and 2 weak lateral setae. Mesoscutum much wider than long, shorter than scutellum; midlobe of mesoscutum with a pair of strong, long setae. Dorsellum of metanotum ( Figs 2 , 5, 6 ) with posterior margin widely angulate medially. Propodeum ( Figs 2 , 5, 6 ) with curved submedial carinae; these not meeting posteriorly and meeting or almost meeting at anterior margin of propodeum, extending to its anterior margin. Propodeum more or less smooth between submedial carinae but between submedial and lateral carinae with conspicuous transverse wrinkles, and with cellulate sculpture lateral to lateral carinae. Protibia without conical sensilla; metacoxa finely, inconspicuously sculptured.

Forewing ( Fig. 4 ) 3.5–3.7 x as long as wide; marginal setae short, the longest marginal seta 1/5–1/4 greatest wing width. Forewing blade slightly infumate throughout, bare behind submarginal and marginal veins except for a few setae at apex of marginal vein, remainder of the blade densely setose. Submarginal vein with 1 macrochaeta and 2 smaller setae, marginal vein with 4 or 5 setae between proximal and distal macrochaetae. Hind wing 19–23 x as long as wide, the blade slightly infumate and mostly bare except for the usual two complete rows of setae along margins and several scattered setae at apex and an incomplete row of short setae just distal to apex of venation.

Gaster a little longer than mesosoma. Petiole 1.2–1.3 x as wide as long, trapezoidal. Ovipositor 7/10–4/5 length of gaster, not exserted beyond its apex. Ovipositor length: mesotibia length about 1.0. Outer plates of ovipositor each with 1 distal seta.

Measurements of the holotype (in µm, as length or length:width). Mesosoma 529; petiole 58; gaster 584; ovipositor 403. Antenna: radicle 73; rest of scape 212; pedicel 70; F1 45; F2 73; F3 79; F4 79; F5 70; F6 64; F7 67; F8 58; clava 242. Forewing 1341:381; longest marginal seta 91. Hind wing 984:45; longest marginal seta 109.

MALE (paratypes). Body length 1.1–1.4 mm. Body color usually a little (but sometimes notably) darker than in female, particularly of mesonotum and gastral terga (mostly brown, with some light brown); scape and pedicel light brown, flagellum brown to dark brown. Antenna ( Fig. 7 ) with scape and radicle fused, scape (excluding radicle) 2.7–3.4 x as long as wide, pedicel very small, F1 the shortest and widest flagellar segment; all flagellomeres longer than wide and with 10–12 longitudinal sensilla. Forewing ( Fig. 9 ) 3.4–3.5 x as long as wide. Genitalia as in Fig. 8 ; apex of apodeme of genital sternite more or less rounded.

Diagnosis

Member of the ater species group of Gonatocerus , as defined by Huber (1988), and its morrilli subgroup, which is characterized by a usually conspicuously rugose propodeum, particularly posteriorly. The petiole in the species belonging to this subgroup is usually (but not always, as in the case of G. virlai ) distinctly longer than wide. Among the described species of Gonatocerus in the New World, the following ones belong to the morrilli subgroup of the ater group: G. annulicornis (Ogloblin) , G. coxalis (Ogloblin) , G. grandis (Ogloblin) , G. h e l a v a i Yo s h imo t o, G. morgani S. Triapitsyn , G. morrilli (Howard) , G. quirogai (Ogloblin) , G. tuberculifemur (Ogloblin) , and G. walkerjonesi S. Triapitsyn. Among these, G. annulicornis , G. morgani , G. morrilli , G. quirogai , and G. walkerjonesi have white or contrastingly lighter funicle segments of the female antenna. Gonatocerus annulicornis and G. walkerjonesi cluster with G. virlai sp. n. molecularly (de León et al. 2006a,b,c), thus supporting their inclusion in the same subgroup. The female flagellum is all brown to dark brown, without white or light funicular segments, in G. c o x a l i s, G. v i r l a i, and G. tuberculifemur . Gonatocerus coxalis differs from G. virlai in having a conspicuous subapical brown spot on the female forewing blade (forewing blade slightly infumate throughout in G. v i r l a i). The propodeum of the dark brown-colored G. tuberculifemur is not rugose as in G. virlai but smooth between the submedial carinae and elsewhere with a faint cellulate sculpture. The male of G. grandis , for which females are not known, differs from the male of G. virlai by its much larger body size (body length of the slide-mounted specimens 1.8–2.4 mm) and also by a hyaline forewing. The male of G. h e l a v a i, which is known from the male sex only, has branched antennae and a very long petiole (much longer than wide).

Gonatocerus virlai does not match the descriptions and types of any of the numerous species of Gonatocerus from Argentina and elsewhere in South America described by A.A. Ogloblin and others [the senior author examined all of them (except for one lost type of an unrelated species from Ecuador, which belongs to the membraciphagus species group) for the forthcoming revision of the described Neotropical species of Gonatocerus (Triapitsyn 2006b) ].

Comments

Interestingly, A.A. Ogloblin also recognized this as a new species because the female specimen (now a paratype of G. v i r l a i) from Loreto, Misiones, is labeled using his manuscript name “ Gonatocerus loretoensis ”.

Etymology

This species is named after our colleague and friend (and co-author of this communication) Eduardo G. Virla, who first reared it from the eggs of T. rubromarginata and also studied its biology.

Natural hosts

Cicadellidae (Proconiini) : Tapajosa rubromarginata (Signoret) as well as Dechacona missionum (Berg) and Molomea consolida Schröder (the latter two from the sentinel eggs only). Also Cicadellini : Ciminius platensis (Berg) and Plesiommata mollicella (Fowler) (from sentinel eggs only).

Laboratory and apparently unnatural hosts

Cicadellidae (Proconiini) : Homalodisca vitripennis (Germar) as well as Oncometopia tucumana (Schröder) , Tapajosa similis (Melichar) , and Tretogonia notatifrons Melichar.

Comments

Our laboratory (no-choice) and field host range studies revealed that G. v i r l a i readily parasitized eggs of Proconiini , although occasionally it also attacked sentinel eggs of two leafhopper species from the Cicadellini (E.G. Virla unpublished data). Biological traits of this species will be reported elsewhere (E.G. Virla and G.A. Logarzo in preparation).

Figures

FIGURES 1 – 4. Gonatocerus virlai (female, holotype). 1. Antenna. 2. Dorsellum and propodeum. 3. Mesosoma and metasoma. 4. Forewing.

FIGURES 5, 6. Gonatocerus virlai (female, scanning electron micrographs). 5. Mesosoma. 6. Dorsellum and propodeum.

FIGURES 7 – 9. Gonatocerus virlai (male, paratypes). 7. Antenna. 8. Genitalia. 9. Forewing.