Brethesiella mojave V. Trjapitzin & S. Triapitsyn, 2006

Trjapitzin, Vladimir A. & Triapitsyn, Serguei V., 2006, A new species of Brethesiella (Hymenoptera: Encyrtidae) from California, USA, a parasitoid of Steatococcus tabernicolus (Hemiptera: Margarodidae), Zootaxa 1167, pp. 1-16 : 7-11

Brethesiella mojave V. Trjapitzin & S. Triapitsyn , sp. n.

( Figs 1–7 )

Type material

Holotype female on card, labeled: 1."Ex Steatococcus tabernicolus Ferris "; 2."On Creosote bush"; 3."Little Rock, Calif."; 4." F. R. Platt, Apr. 1936 "; 5." Brethesiella sp., c.f. latifrons (Timb.) . Det. J. W. Beardsley "; 6. Brethesiella mojave V. Trjapitzin & S. Triapitsyn HOLOTYPE female". Holotype deposited in UCRC. Paratypes: 4 females and 1 male on points [ UCRC], 1 female on point [ BMNH], 1 female on point [ USNM], and 1 female and 1 male on slides [ ZISP], same data as the holotype.

Diagnosis

The new species belongs to the latifrons species group of Brethesiella , as defined above, and is most similar to B. longipes by having a well developed postmarginal vein of the forewing and a relatively long pedicel of the female antenna. The differences between these species are indicated in the key. The forewing of B. mojave is rather broad for the genus. The male of B. mojave is more similar to that of B. coccidophaga in having subquadrate funicle segments (except for F1) and a black dorsum of the mesosoma.

Description FEMALE (holotype and paratypes). Length 1.3–1.6 mm (holotype 1.3 mm). Color. Body orange­brown. Antenna blackish­brown. Dorsal part of pronotum and apical 2/3 of scutellum dusky, with violet­greenish­bronze luster. Tegula more or less dark, with bronze luster, sometimes with brown base. Mesopleuron dark, with greenish­violet luster, but its anterior part brownish. Forewing infuscated in the middle ( Figs 3, 4 ). All coxae as well as fore and mid femora brownish­yellow; hind femur black. Foretibia brownish­black; middle tibia black, with brownish apex; hind tibia completely black; mesotibial spur yellowish­white. Foretarsus dusky or black; middle tarsi yellowish­white, with darkened apical segment; hind tarsus the same color but with three last segments darkened. Gaster dark, with brown base. Exserted part of ovipositor sheaths yellow­ brown.

Sculpture. Frontovertex, dorsal part of pronotum, axilla, scutellum, lower part of mesopleuron and lateral parts of propodeum with minute cellulate sculpturing; upper part of mesopleuron with larger sculpture cells. Mesoscutum very minutely reticulate.

Pubescence. Postico­lateral parts of propodeum with dense silvery­white pubescence. Lower part of face beneath toruli with very thin and short, scattered silvery­white setae.

Head slightly higher than wide. Vertex in frontal view strongly convex, about 1/2 head width or a little more (up to 9:16). Occipital margin concave. Inner orbits of eyes strongly diverging anteriad. Temples shorter than distance from posterior ocellus to occipital margin. Ocelli in a triangle (about 90°); distance between posterior ocelli (POL) more than distance from posterior ocellus to anterior ocellus (AOL); posterior ocelli noticeably closer to eye margins (OOL) than to occipital margin (OCL). Scrobes very short, not meeting above. Malar (subocular) suture present. Palpi very small and thin; palpal formula 4: 3.

Antenna ( Fig. 1 ) inserted distinctly below level of lower eye margin. Scape about 5.6x as long as wide. Pedicel about as long as combined length of F2 and F3. F2­F6 more or less subquadrate except F3 sometimes a little longer than wide. Clava about 2x as long as its greatest width and as long as combined length of 3 preceding flagellar segments.

Mesosoma ( Fig. 2 ). Pronotum campanulate, its posterior margin slightly concave. Mesoscutum rather narrow, 1.5x as long as entire pronotum and about 2x as wide as long. Axilla narrow, with acute apex. Scutellum almost flat and as long as wide, somewhat longer than mesoscutum (4:3); lateral margins of scutellum strongly converging posteriorly and almost straight, scutellar apex narrowly rounded and overhanging the median part of propodeum.

Wings not abbreviated, reaching far beyond apex of gaster. Forewing ( Fig. 3 ) 2.3–2.4x as long as its maximum width. Costal cell about 10x as long as wide. Marginal vein longer than wide ( Fig. 4 ); postmarginal vein well developed but somewhat shorter than stigmal vein.

Legs. Basitarsus of middle leg as long as combined length of following mesotarsal segments; mesotibial spur as long as mesobasitarsus.

Metasoma ( Fig. 2 ). Ovipositor occupying entire length of gaster, exserted part of ovipositor 1/6–1/7 of its total length; ovipositor length /hind tibia length ratio about 1.25:1.

MALE (paratypes). Length 1.3–1.4 mm. Vertex and posterior part of malar space brownish­black; dorsal part of mesosoma and gaster black, with light violet luster; base of tegula brownish. Ocelli larger than in female. Scrobes united above. Toruli immediately beneath level of eye margin. Cellulate sculpturing on vertex not so minute as in female. F2­F5 subquadrate, F6 a little longer than wide; clava about as wide as F6, about 3x as long as wide, and dorsally obliquely truncate at apex ( Fig. 5 ). Mesoscutum 1.7–1.8x as long as wide. Scutellum a little longer than wide (5:4). Forewing hyaline, only with a light infuscations next to base of submarginal and also next to postmarginal and stigmal veins ( Fig. 6 ). Genitalia as in Fig. 7 .

Etymology The specific name refers to the Mojave Desert in California, USA.

Comments A mummy of the margarodid host (glued onto the same card with one of the paratypes) has many exit holes, indicating that B. mojave is a gregarious parasitoid.

Figures

FIGURES 1, 2. Brethesiella mojave, sp. n. (female, paratype). 1. Antenna. 2. Mesosoma and metasoma.

FIGURES 3, 4. Brethesiella mojave, sp. n. (female, paratype). 3. Forewing. 4. Forewing venation.

FIGURES 5, 6. Brethesiella mojave, sp. n. (male, paratype). 5. Antenna. 6. Base of forewing.

FIGURES 7, 8. Brethesiella spp. 7. B. mojave, sp. n., male genitalia (paratype). 8. B. flava, forewing venation (female, holotype).