Gonatocerus uat S. Triapitsyn

Triapitsyn, Serguei V., Vickerman, Danel B., Heraty, John M. & Logarzo, Guillermo A., 2006, A new species of Gonatocerus (Hymenoptera: Mymaridae) parasitic on proconiine sharpshooters (Hemiptera: Cicadellidae) in the New World, Zootaxa 1158, pp. 55-67 : 58-62

Gonatocerus uat S. Triapitsyn , sp. n.

( Figs 1–5 )

Type material

Holotype female on slide [ UCRC], labeled: 1." MEXICO, San Luis Potosí, Ciudad Valles, 28.iii.2001, D. Morgan, C. Pickett, S. Myartseva, A. Ríos. Ex. Homalodisca sp. egg mass on hibiscus leaf. S & R 01­05­10 ­A. Mounted by V. Berezovskiy 2001 Canada balsam"; 2. (red) " Gonatocerus uat S. Triapitsyn HOLOTYPE female". Paratypes: MEXICO. San Luis Potosí, Ciudad Valles, same data as holotype [1 female on slide, CNCI]. Tamaulipas: Gómez Farías, 23°02’56’’N, 99°09’24’’W, 26.iii.2001, D. J. W. Morgan, C. Pickett, S. N. Myartseva, A. Ríos (ex. Oncometopia sp. egg mass) [1 female in ethanol, kept in a freezer, UCRC]; 28.iii.2001, D. J. W. Morgan, C. Pickett, S. N. Myartseva, A. Ríos (ex. Oncometopia sp. egg mass) [1 female on slide, UCRC]; 13.iii.2003, S. V. Triapitsyn, E. Ya. Shouvakhina, S. N. Myartseva (ex. Homalodisca sp. or Oncometopia sp. egg masses on orange leaves; emerged 15.iii. 2003 in Ciudad Victoria, Tamaulipas) [2 females on slides (except mesosoma of one of them on stub for SEM), E MUT, UCRC; 2 females on points, UCRC, USNM; and 1 male on slide, UCRC].

Additional material examined [all in UCRC]

ARGENTINA. Jujuy, Santa Clara: 24.i.2001, G. Logarzo, 4 females, 3 males (ex. sentinel eggs of Tapajosa rubromarginata (Signoret) on citrus); 12–21.ii.2002, G. Logarzo, 4 females, 1 male (ex. sentinel eggs of T. rubromarginata , died on route to USDA­APHIS Mission quarantine laboratory in Edinburg, Texas, USA); 13.iv.2003, G. Logarzo, 1 female (ex. egg mass of an unidentified proconiine sharpshooter on mandarin). Originally from: Tucumán, Tafí Viejo, 1–18.iii.2002, E. Virla (ex. sentinel eggs of T. rubromarginata on lemon), first generation progeny of an unfertilized female (23 males, emerged 17.iv.2002) in USDA­APHIS Mission quarantine laboratory in Edinburg, Texas, on eggs of H. coagulata . MEXICO. Tamaulipas, Llera de Canales, 23°18’58’’N, 99°01’30’’W, 8.iii.2000, L. G. Bezark, S. V. Triapitsyn, 1 female, 1 male (ex. proconiine sharpshooter ( Homalodisca sp. or Oncometopia sp.) egg mass on hibiscus leaf, emerged 23.iii. 2000 in University of California, Riverside quarantine laboratory). PERU. Junín, Chanchamayo, Genova (near La Merced), Fundo farm, G. Logarzo, L. Varone, 8 females, 1 male (ex. eggs of Oncometopia n. sp., Pseudometopia amblardii (Signoret) and P. phalaesia (Distant) , caged 9–10.v.2002 on Satsuma mandarin (Citrus reticulata var. satsuma ), emerged 17.v–3.vi. 2002 in University of California, Riverside quarantine laboratory).

Description

FEMALE (holotype and paratypes). Body length 1.6–2.0 mm. Head and mesosoma ( Fig. 2 ) mostly dark brown except for face (light brown) and occiput (pale); mesosomal sternum with distinct, well­defined yellow streak between fore­ and middle coxae, very similar to those in G. ashmeadi , as described by Huber (1988). Scape light brown, other antennal segments brown to dark brown. Legs mostly pale yellow, hind femur (distally only) and hind tibia notably darker (brown). Petiole light brown; gaster ( Fig. 2 ) mostly pale, with 4 transverse brown bands on terga IV–VII and 2 brown spots on tergum VIII, tergum IX light brown; inner and outer ovipositor plates and cercal plates brown.

Antenna with radicle about 2.3x as long as wide, scape ( Fig. 1 ) about 2.7x as long as wide, almost smooth, with several rows of strong setae; pedicel ( Fig. 1 ) shorter than F1 and almost smooth; F1­F4 usually subequal in length but F1 and/or F3 sometimes a little shorter than F2, F5­F8 each progressively shorter than preceding funicle segment; F1 ( Fig. 1 ) almost always with 2 longitudinal sensilla, rarely with 1 sensillum, F2­F8 each with 2 longitudinal sensilla; all funicle segments densely setose; clava with 8 longitudinal sensilla, about 2.8x as long as wide, a little wider than scape (in lateral view), and nearly as long as combined length of F1­F3; its ventral surface covered with numerous minute, short setae and placoid sensilla, its dorsal surface densely covered with longer setae.

Pronotum divided medially, each lobe with 2 dorsal and 1 lateral setae. Mesoscutum much wider than long, a little shorter than scutellum; midlobe of mesoscutum with a pair of strong setae. Dorsellum of metanotum ( Fig. 5 ) with posterior margin slightly angulate medially. Propodeum ( Fig. 5 ) with well­developed lateral carinae and slightly curved submedial carinae (meeting near anterior and posterior margins of propodeum, notably wider anteriorly); propodeum almost smooth between submedial carinae but slightly wrinkled (posteriorly only) between submedial and lateral carinae. Foretibia with 3–7 conical sensilla. Forewing ( Fig. 3 ) 3.4–3.7x as long as wide; marginal setae short, the longest marginal seta about 1/5 maximum wing width. Forewing disc notably infuscated beyond venation, bare behind submarginal vein, with several scattered setae behind marginal and stigmal veins, cubital row of setae complete, remainder of blade densely setose. Submarginal vein with 1 macrochaeta, marginal vein with 5 or 6 microchaetae between proximal and distal macrochaetae. Hind wing 16–17x as long as wide, the blade bare except for the usual two complete rows of setae along margins and several scattered setae at apex and behind tip of venation.

Petiole almost as long as wide, subquadrate. Ovipositor about 3/4 length of gaster, barely exserted beyond its apex. Ovipositor:mesotibia ratio 1.0–1.1. Outer plates of ovipositor each with 1 distal seta.

Measurements of the holotype (in µm, as length, or length:width ratios). Body 2005; head 283; mesosoma 695; petiole 76; gaster 1027; ovipositor 558. Antenna: radicle 78; scape 191; pedicel 76; F1 97; F2 107; F3 95; F4 100; F5 92; F6 82; F7 76; F8 68; clava 276. Forewing 1596:474; longest marginal seta 97. Hind wing 1107:49; longest marginal seta 102.

MALE (paratype on slide). Body length (before slide­mounting) 1.4 mm. Similar to female in coloration. Antenna ( Fig. 4 ) with scape and radicle fused, scape (excluding radicle) about 2x as long as wide; pedicel very small, basal flagellomeres a little wider than distal ones, all flagellomeres with numerous longitudinal sensilla. Forewing about 3.6x as long as wide; infuscation of its disc perhaps slightly less conspicuous than in female. Genitalia very similar to those in G. ashmeadi .

Etymology

This species is named after the Universidad Autónoma de Tamaulipas in Ciudad Victoria, Tamaulipas, Mexico, which is commonly abbreviated there as U.A.T.

Diagnosis

In Huber’s (1988) key to the North American species of the ater group, G. uat would key to G. ashmeadi . The known distribution of G. ashmeadi is strictly within the Nearctic region (S. V. Triapitsyn, unpublished) whereas G. uat is mainly a Neotropical species; these two taxa might be sympatric only in the Ciudad Victoria area of Tamaulipas, Mexico. Although presently G. ashmeadi is not known South of Ciudad Victoria and G. u a t is not known North of Llera de Canales; both locations are formally placed within the Nearctic region but have many Neotropical elements. The specimens of G. ashmeadi from Venezuela, mentioned by Huber (1988) but not examined by us (material is not available), thus probably belong to G. u a t.

The following morphological features distinguish this new species from G. ashmeadi : F1 of female antenna ( Fig. 1 ) almost always (in specimens from Mexico and Peru) with 2 longitudinal sensilla, rarely with 1 sensillum (always none in G. ashmeadi ); the propodeum ( Fig. 5 ) is slightly wrinkled (distal half only) between submedial and lateral carinae and the submedial carinae meet near anterior margin of propodeum, whereas in G. ashmeadi the propodeum ( Fig. 6 ) is almost smooth between submedial and lateral carinae and the submedial carinae do not meet near anterior margin of propodeum; the submedial carinae on the propodeum are notably wider anteriorly in G. uat than in G. ashmeadi ( Figs 5, 6 , respectively); the forewing disc is notably infuscated beyond the venation ( Fig. 3 ), and more conspicuously so behind the tip of the marginal vein (hyaline or at most with a faint, uniform brownish tinge in G. ashmeadi , Fig. 7 ). Also, the female forewing of G. u a t from Mexico (length:width ratio 3.4–3.7, 3.5–3.6 in most specimens) is somewhat narrower than that of G. ashmeadi (length:width ratio 3.0–3.4, 3.2–3.3 in most specimens). Gonatocerus uat is morphologically very similar to and, as we conclude from the molecular evidence presented below, conspecific with the forms from Argentina and Peru, which were tentatively identified previously as G. sp. near ashmeadi by Logarzo et al. (2003). Neither the Mexican nor Argentine nor Peruvian specimens of G. u a t match the descriptions and available types of any of the numerous species of Gonatocerus from Argentina and elsewhere in South America described by A. A. Ogloblin and others.

Var ia t io n. The forewings of G. uat from Argentina and Peru are somewhat wider (length:width ratio about 3.1) than from Mexico (length:width ratio 3.4–3.7). As reported by Logarzo et al. (2003), the Peruvian specimens of G. uat displayed a dramatic body size variability, which was apparently host­induced; body length of dry­mounted females reared from the very large eggs of Oncometopia n. sp. was 1.9–2.1 mm whereas for individuals reared from the notably smaller eggs of Pseudometopia amblardii (Signoret) and P. phalaesia (Distant) it was 1.4–1.5 mm (also very similar to the body size of females reared at the University of California, Riverside quarantine laboratory on a factitious host, H. coagulata ). The body length of dry­mounted females from Argentina, reared from the even smaller eggs of Tapajosa rubromarginata (Signoret) , was also significantly less (1.0– 1.2 mm) than of those reared from all of the larger, aforementioned hosts. In the smaller specimens from Argentina, often F1 and sometimes F2 of the female antenna lack one or both longitudinal sensilla.

Figures

FIGURE 7. Forewing of Gonatocerus ashmeadi (California, USA).

FIGURES 1 – 4. Gonatocerus uat (paratypes). (1) Scape, pedicel, and first two funicle segments of antenna (female); (2) Body (female); (3) Forewing (female); (4) Antenna (male).

FIGURES 5, 6. Scutellum (posterior part only), metanotum, and propodeum (female, scanning electron micrographs, magnification 200 x). (5) Gonatocerus uat (San Luis Potosí, Mexico); (6) Gonatocerus ashmeadi (Tamaulipas, Mexico).