Euteloida basalis Burks

Burks, R. A. & Redak, R. A., 2004, New species of Pteromalidae and Torymidae (Hymenoptera: Chalcidoidea) from California, with taxonomic notes, Zootaxa 606, pp. 1-20 : 14-16

Euteloida basalis Burks , n. sp.

Diagnosis. Basal cell of forewing bare to at most with 5 tiny ventral setae and 2 dorsal setae (these in males only). Costal cell without dorsal setae. Temples short, at most 0.15x dorsal eye length in females.

Description. Females. Body length 1.8–3.0 mm (9.8–16.4 in relative units used below).

Color: Head and mesosoma dark to brassy metallic green to blue, paler specimens with a purplish blotch on mesoscutum centrally to posteriorly; eye and ocelli pale pinkishwhite. Gaster mostly metallic bluish­green to brown, but adpetiolar area conspicuously orange in paler specimens. Mandibles reddish­brown, maxillary and labial palps brown. Scape yellowish brown, becoming darker in apical half in most specimens but only slightly so in pale specimens; pedicel and flagellum dark brown with white longitudinal sensilla; club becoming light brown apically. Tegula and humeral plate brown. Venation mostly brownish but marginal vein becoming opaque whitish except for periphery. Legs mostly very light brown to nearly yellow, but coxae and all but apices of femora metallic green to brownish, pro­ and mesotibiae slightly fuscate apart from apices, and each apical tarsomere brown.

Sculpture: Most of head and thorax alveolate, except clypeus entirely striate, upper mesepimeron and acropleuron completely smooth. Prepectus alveolate. Mesothoracic venter strongly alveolate. Dorsellum very shallowly and transversely alveolate. Metapleuron alveolate, with a circular pit at postero­dorsal and postero­ventral corners. Propodeum almost entirely alveolate, but anterior plical pits smooth, callus with a small vague bumplike elevation in posterior half. Nucha very shallowly alveolate to nearly smooth. Petiole smooth.

Head width 3.1–5.6, height 2.5–4.4, length 1.2–2.0; dorsal IOD 2.0–3.6; ventral IOD 2.4–4.2; bottom of toruli intersecting lower eye margin; ITD 0.2–0.3; VTD 1.5–2.6; MTD 0.8–1.4; ocular setae short, equal or shorter than diameter of an adjacent ommatidium; clypeus shallowly emarginate; EH 1.3–2.2; MS 1.1–1.6; MW 1.3–2.3; POL 0.8–1.3; OOL 0.5–0.9; EL 1.1–1.6; TL 0.1–0.2; malar sulcus complete but extremely faint; setae short and not broadened. Flagellum and pedicel as in Fig. 14; scape 1.2–2.1:0.1–0.2; pedicel 0.4–0.6:0.2–0.3; scape at rest reaching bottom of median ocellus; all funicular segments transverse, funicular and claval segments with 1 row of longitudinal sensilla; club with asymmetrical sutures and a large ventral sensory area with a divided pair of micropilose areas, the apical area smaller than the basal one. Left mandible with 3 denticles including as one a dorsal truncation, the right mandible with 4 denticles.

Mesosoma (Figs. 12–13, 15–16). Pronotal collar medial length 0.3, hardly longer laterally than medially, width 2.5; mesoscutum length:width 1.4–2.5:2.4–4.2; scutellum 1.2– 2.2:1.3–2.5; dorsellum extremely short; propodeum length 0.7–1.6. Pronotal collar smoothly rounded anteriorly; collum steep, visible dorsally for a length of 0.2–0.3; lateral panel of pronotum with a deep, narrow, smoothly arched scrobe completely overhung by the protruding shoulder and ending in anterior face of pronotum (its ending not visible dorsally); axillae weakly advanced, anterior separation 0.3–0.6; axillulae about half scutellar height; scutellum distinctly more convex than mesoscutum, with a very short sculpted posterior rim set off by a shallow furrow; frenal groove indistinct but indicated by the presence of 4 inclinate setae; dorsal margin of prepectus slightly longer to slightly shorter than tegula; mesothoracic venter with a vaguely formed shelf anterior of mesocoxae, but the shelf rounded anteriorly, not carinate; posterior pit deep and surrounding area with steep sides. Propodeum with at most a very weak median carina; plicae faintly indicated at anterior and posterior extremes, apparently curving to meet across nuchal base, ISD 1.2–2.3; anterior plical pits deep and nearly circular; posterior plical pits extremely shallow and indistinct; spiracles emarginate; postspiracular furrows shallow but uninterrupted; callar setae numerous and present from callus mesally to behind spiracle along supracoxal flange; supracoxal flange about as long as the lesser axis of the spiracle and becoming narrower only at nuchal apex, not crossed by any carinulae; no indication of a costula or anterior plicae; nucha short but convex, medial length 0.3–0.5, apical width 0.6–1.1; nuchal apex projecting maximally 0.2–0.5 past supracoxal flange at metacoxal base. PRF 1.7– 2.7:0.4–0.8; PRT 1.5–2.6:0.3–0.4; MSF 1.6–2.7:0.4–0.7; MST 2.1–3.4:0.3–0.4; mesotibial spur 0.4–0.6; basal mesotarsomere 05–1.0; MTF 2.0–3.4:0.5–0.9; MTT 2.3–3.3:0.3–0.5; metatibial spur 0.2–0.4; basal metatarsomere 0.5–1.1. FW (Fig. 15) 7.0–11.5:3.2–5.2; CC 2.6–4.3; MV 1.5–2.6; PMV 1.2–1.7; SV 0.9–1.5, shortest distance from uncal apex to PMV 0.4–0.5, shortest distance from stigmal apex to PMV 0.6–0.9; uncus 0.33x greatest stigmal width; costal cell with one row of ventral setae having a short middle interruption, with a few scattered setae in apical quarter, without dorsal setae; speculum extending from parastigma and posteriorly open except for a few setae near subcubital area; four to five vague rows of short admarginal setae present but not exposed by speculum; basal cell bare, basal fold with a row of setae; cubital and subcubital folds setose until reaching speculum. HW 5.3–9.0:1.2–2.3, not different from the typical pteromaline form.

Petiole over 2x broader than long, conical, broadly emarginate posteriorly. Gaster length 5.2–8.2; gt1 the longest, with a distinct but short convex posterior lobe; gs1 with a weak basal flange that is unsculptured and broadly divided ventrally; hypopygium ending 2.3–3.3 from gastral base; ovipositor sheaths hardly extending beyond gastral apex.

Males. Body length 1.6–1.8 mm (8.5–9.6 in relative units). Like female, except for the following characters: scape not quite reaching median ocellus, 1.1–1.3:0.1–0.2; pedicel 0.3–0.4:0.2–0.3; flagellum and pedicel in Fig. 11, flagellum with few longitudinal sensilla but densely covered with short curved setae, the segments separated by short but distinct stalks; club with symmetrical sutures, without distinct sensory area, not acuminate; posterior smooth strip of pronotum almost or quite as distinct medially as laterally; petiole with a tiny subapical lateral denticle on each side; gaster without a pale subbasal blotch.

Variation: Top of toruli intersecting lower eye margin in some specimens. Scape not reaching median ocellus in some small specimens. Normal females with an extremely short posterior pronotal strip, but males and smaller females with a longer one. Nuchal apex variably emarginate, sometimes strongly so as in the holotype of E. subnigra , sometimes nearly truncate. Basal cell of forewing in some males with up to 5 tiny ventral setae centrally and/or apically (this in some males) and at most 2 dorsal setae, present near the basal fold. Stigmal shape variable, becoming more rounded and nearly isodiametric in smaller specimens, but similar in size and scope to that of the holotype in larger specimens. Propodeal carinae variable: some specimens with more or less distinct posterior plical remnants and plical pits near nuchal base, the plicae faintly meeting across nuchal base, and with or without a preapical furrow across nuchal midpoint.

Host: Unknown.

Distribution: Riverside and Los Angeles Counties, California, USA, all from coastal sage scrub habitat.

Etymology: Named after the dorsally bare basal cell of the forewing.

Holotype Ψ, allotype ɗ, and 1 paratype Ψ USA: CA: Riverside Co. Lake Skinner (NE End) 33° 36 7 N 117° 2 5 W 3–16.iii.1997 J.D. Pinto MT Coastal Sage Scrub METU11 UNBURNED (USNM). 1 Ψ and 1 ɗ paratype Riverside Co. Lake Skinner (NE End) 33° 36 7 N 117° 2 5 W 10–24.iv.1997 J.D. Pinto MT Coastal Sage Scrub (UCRC). 1Ψ and 1 ɗ paratype Riverside Co. Lake Skinner (NE End) 33° 36 7 N 117° 2 5 W 3–16.iii.1997 J.D. Pinto MT Coastal Sage Scrub (UCDC). 1 Ψ paratype Riverside Co. Lake Skinner (NE End) 33°36 117°2 W 5.iii.1998 Redak Lab UCR (UCRC). 1 Ψ paratype Riverside Co. Lake Skinner (NE End) 33°36 117°2 W 17.iii.1998 Redak Lab UCR (UCRC). 1Ψ and 5ɗ paratypes Riverside Co. Lake Skinner (NE End) 33°36 117°2 W 23.x­6.xi.1997 J.D. Pinto MT Coastal Sage Scrub METU4 UNBURNED (UCRC). 1 Ψ paratype Los Angeles Co. San Pedro 3171 N. Gaffey St. DFSP Malaise coastal sage scrub xi.16 – xii.11.2001 J. George (LACM). 2 ɗ paratypes Los Angeles Co. San Pedro 3171 N. Gaffey DFSP Malaise coastal sage scrub xi.8 –16.2001 J. George (LACM).

Discussion. This species differs from Euteloida subnigra Bouček most significantly in the characters listed in the diagnosis section above. In contrast, E. subnigra has an almost entirely setose basal cell (Fig. 16) with numerous dorsal setae and a setose cubital fold, temples 0.15– 25 x dorsal eye length, and costal cell with some dorsal setae in its apical third and generally with more ventral setae than in E. basalis . The temple length character is difficult to use, as the head must be exactly vertical, and measurements must be taken exactly as done by Graham (1969), but this character is valuable if correctly assessed. Some features of E. subnigra not noted in the original description: nucha with a complete wrinkle­like carina across its base, abruptly turned anteriad at a rounded right­angle around posterior plical pits. These plical remnants proceed diagonally from the nuchal base in specimens of E. basalis in which they are present, and are much more shallowly curved. I (RAB) found another specimen of E. subnigra from Texas (TAMU) and Steve Heydon (UCDC) has shown me several other specimens from Mississippi and Louisiana.