Venanus heberti Fernandez-Triana

Fernandez-Triana, Jose L., 2010, Eight new species and an annotated checklist of Microgastrinae (Hymenoptera, Braconidae) from Canada and Alaska, ZooKeys 63, pp. 1-53 : 21-25

Venanus heberti Fernandez-Triana sp. n. Figs 19, 20

Venanus pinicola Mason, 1981: 95 (in part). [Examined].

Type locality.

Canada, Prince Edward Island, Blooming Point, 46°24.486'N, 62°57.062'W.

Type material.

Holotype. Male (CNC), with labels as follows: CANADA: PEI, Blooming Point, 46°24.486'N, 62°57.062'W, 23.vii.2008, fallow field, 6m, Goulet, Boudreault & Badiss, sweeping, #16. Second label with Specimen ID: MIC 000476. CNC TYPE 23942.

Paratypes (CNC): 1 ♀ Annapolis Royal, NS, 7.ix.1945, J. McDunnough, ex Microlep. on Gaylussacia ; 2 ♂ same data than holotype (Specimen ID: MIC 000474 and MIC 000475); 1 ♂ Bridgetown, NS, 2.ix.12, JES; 1♂ Sable Island, NS, 11-15.ix.1967, W.R.M. Mason; 1 ♂ Halifax, NS, 15.viii.1954, J. McDunnough, ex Caloptilia asplenifoliella ; 1 ♂ Knowlton, QC, 19.viii.1929, G. S. Walley, ex larva on Myrica ; 1 ♂ Kazabazua, QC, 19.viii.1933, G. S. Walley, ex larva on blueberry.

Diagnosis.

Venanus heberti is similar to Venanus pinicola Mason, 1981, and will run to that species in the recent key to the New World species ( Whitfield et al. in press). Venanus pinicola is smaller (females: 1.6-1.9 mm, average=1.7 mm, N=8; males 1.7-2.4 mm, average=2.0 mm, N=5) than Venanus heberti (female: 2.2 mm; males: 2.0-2.4 mm, average=2.2, N=8). The size (width and height) of the second submarginal cell in the fore wing (compared to the length of vein r, the width and the length of stigma) is smaller in Venanus pinicola -usually the values represent 0.6-0.8 of similar proportions for Venanus heberti . The males of Venanus pinicola have its veins mostly pigmented (as have the females of both species), contrasting with mostly unpigmented veins in males of Venanus heberti . The two species have different geographical distributions: Venanus pinicola in west Canada/US (AB, BC, YT and ID) and Venanus heberti in Eastern Canada. The known hosts are different: the Gelechids Coleotechnites milleri (Busck, 1914) and Coleotechnites starki (Freeman, 1957) for Venanus pinicola ; and the Gracillarid Caloptilia asplenifoliella (Darlington, 1949) for Venanus heberti . The two species also differ in 12 base pairs of the barcode region (more details below under the sections Molecular data, Distribution and biology and Comments).

Description.

Male

Antenna length 2.4 mm (1.9-2.4 mm), body length 2.4 mm (2.0-2.4 mm), forewing 2.1 mm (2.0-2.2 mm). Head with glossa truncate and short. Face smooth, with shallow punctures (separation between punctures larger than punctures diameter) and sparse, uniformly distributed setae. Face width at antennal base/face width at clypeus edge: 1.1 ×; intertentorial pit distance/face width at clypeus edge: 0.5 ×; compound eye height/head height: 0.7 ×; head height/width: 0.7 ×; face width at antennal base/head maximum width: 0.6 ×; malar space/basal width of mandible 1.0 ×. Clypeus transverse, its width/height: 3.6 ×. Ocelo-ocular distance/posterior ocelli diameter: 2.0 × (2.0 –2.4×); distance betwen posterior ocelli/ocelli diameter: 2.0 ×.

Mesosoma. Pronotum very smooth and polished, laterally with only the ventral groove well defined. Mesoscutum mostly smooth, with shallow but close punctures (distance between punctures 0.5-0.7 its diameter), punctures a sparser centrally along the posterior margin. Mesoscutum 1.2 × (1.1 –1.2×) wider than long. Mesoscutum and scutellum covered by sparse, silvered-coloured pilosity (sparser in the scutellum). Scutellum mostly smooth, with a few, shallow, very sparse punctures. Scutellum length/width at base 1.0 ×. Scutellar suture width 1/7 scutellum length, with 16 costulae not very well defined. Posterior band of scutellum polished. Scutellar lateral face with the polished area semicircular, 0.3 –0.4× the face height. Mesopleuron smooth and glabrous on most of its surface, with sparse setae and punctures (distance between punctures usually twice or more its diameter) only on the anterior, ventral and posterior margins. Deep sulcus, with costulae, separating meso and metapleura. Metapleuron setose and punctured along anterior and ventral margins; lower ¼ of metapleuron rugulose, and with a broad, crenulated sulcus running from lower margin through spiracle. Metapleural carina lamellate and with costulae. Propodeum mostly rugulose, especially on the apical third (which is concave and delimited from the rest of the propodeum by a vague transverse carina); an obscure longitudinal carinae running centrally from base of propodeum until it reaches the transverse carina; transverse carina intersected posteriorly by several longitudinal, arched ridges radiating from nucha.

Metasoma. Mediotergite 1 widened and rounded apically, with its widest part subapically; basal width/apical width 0.9 ×; length/apical width 1.5; mediotergite 1 rugulose, apical ¼ with longitudinal striation laterally and two pits at each side of a central, polished area (like a knob) that reaches the posterior margin of tergite. Mediotergite 2 trapezoidal in shape, centrally smooth and polished, laterally rugulose; basal width/apical width 0.6 ×; length/apical width 0.6 ×. Mediotergite 3 twice the length of mediotergite 2. Mediotergite 3 and following unsculptured, polished and with few, sparse setae mostly along the posterior margin of tergites.

Legs. Metatibial inner spur 1.2 × the length of outer spur, and 0.6 × the length of metatarsomere 1. Metafemur 2.7 × as long as wide.

Wings. Forewing vein R1a 0.7 × as long as stigma length; length of R1a 2.7 × as long as the distance between its end and the end of 3RSb. Vein r 0.6 × (0.6 –0.7×) the maximum width of stigma. Second submarginal cell height about the same length (or slightly smaller or larger) than vein r length; vein 2M 3.0 × as long as vein (RS+M)b and 0.25 –0.33× the stigma length. Edge of vannal lobe of hindwing covex and uniformly setose.

Colour: Mostly black to dark brown; pro- and meso- tibiae and tarsi yellowish brown, as it is apical 0.2 × of metatibia, metatibial spurs, maxillary and labial palps. Wings hyaline, with most of veins transparent or whitish, except for C+Sc+R, R1, and 2M can be partially or totally pigmented; stigma brwon.

Female

Similar to male but with antenna (~1.0 mm) much shorter than body length (2.2 mm) and fore wing (2.0 mm). Antenna with a single row of placodes. Length/width of flagellomeres: 1st (1.6 ×), 2nd (1.1 ×), 8th (1.1 ×), 14th (1.2 ×), 15th (1.3 ×). Length of flagellomere 2/flagellomere 14: 1.2 ×. Fore wing with most veins slightly pigmented (light brown in colour), and with larger and taller second submarginall cell (length of vein 2M half the stigma length, vein 2M almost twice the length of vein r). Metafemur thicker, 2.1 × as long as wide. Hypopygium not folded nor striate, with slightly pointed tip not protruding beyond apical tergites. Ovipositor sheaths barely exerted from hypopygium, 0.1 × as long as metatibia length; with sparse and minute setae.

Molecular data.

Full barcodesof 3 specimens of Venanus heberti and one specimen of the related species Venanus pinicola were obtained and compared (Fig. 24). The molecular data showed 12 (1.86 %) base pairs of difference between the two species.

Distribution and biology.

The species is widely distributed in Eastern Canada (QC, NS, PE), where it has been realibly reared from Gracillaria asplenifoliella . In the CNC there is one specimen of Venanus heberti from BC with a label stating it was reared from Caloptilia invariabilis (Braun, 1927). This has to be a labelling mistake because Coleotechnites invariabilis is only known from Eastern Canada (NS, ON, QC) and US, but has never been recorded from western Nearctic ( De Prins and De Prins 2010).

Comments.

When Mason (1981) described Venanus pinicola he mentioned some variations in the specimens from Eastern Canada compared to the West, but considered that as intraspecific variation. The consistent, though subtle, morphological and molecular differences; different geographical distribution and hosts provide sufficient evidence to consider them as distinct species. Because of the similarities between the two species, four former paratypes of Venanus pinicola (in the CNC) are here transferred as paratypes of Venanus heberti .

Etymology.

I dedicate this species, recognized after DNA barcoding provided a first clue, to Paul Hebert (University of Guelph), as an appreciation for his support; and also for allowing the gathering of thousand of Microgastrinae barcodes -which will hopefully contribute in a significant way to the taxonomy of such a difficult and diverse group.