Female (CNC), with first label as follows: C-26, Ex Choristoneura rosaceana Harr. on Red Maple; second label: Canterbury, York Co., N.B., 6.vii.1973. CNC TYPE 23936.

(CNC): 3 ♀, 2 ♂ from Canterbury, NB; Galetta, Delta, and North Bay, ON; Old Chelsea and Tenoga, QC; ex: Choristoneura rosaceana (CNC).

Antenna length 2.2–2.3 mm, body length 3.1 mm (3.0–3.4 mm), forewing 3.2 mm (3.2–3.6 mm). Head with glossa truncate and short. Face with shallow punctures (separation between punctures about the same than punctures diameter); and sparse, uniformly distributed setae. Face width at antennal base/face width at clypeus edge: 1.6×; intertentorial pit distance/face width at clypeus edge: 0.6×; compound eye height/head height: 0.7×; head height/width: 0.8×; face width at antennal base/head maximum width: 0.5×; malar space/basal width of mandible 1.3×. Clypeus transversely narrow, its width/height: 3.5×. Length/width of flagellomeres: 1^st (3.9×), 2^nd (3.8×), 8^th (3.0×), 14^th (1.4×), 15^th (1.2×). Length of flagellomere 2/flagellomere 14: 2.6×. Ocelo-ocular distance/posterior ocelli diameter: 2.0×; distance betwen posterior ocelli/ocelli diameter: 2.0×.

Mesosoma. Pronotum laterally with dorsal and ventral grooves well defined. Mesoscutum with relatively close punctures (distance between punctures about 0.5× its diameter). Mesoscutum 1.4× wider than long. Mesoscutum and scutellum uniformly covered by dense, silvered-coloured pilosity. Scutellum almost smooth, with very sparse and shallow punctures mostly on the margins. Scutellum length/width at base 1.0×. Scutellar suture well impressed, with 12 costulae, the central ones more spaced and deeply impressed than the lateral ones. Posterior band of scutellum polished. Scutellar lateral face with polished area semicircular slightly less than half the face height. Mesopleuron setose and with punctures on the anterior half; the posterior half glabrous and smooth except for a thin sulcus running from the posterior margin (at about half the length of that margin) towards the lower margin of mesopleuron (ending just before the punctures and setae of the anterior half). Thin, crenulated sulcus separating meso and metapleura. Metapleuron mostly smooth and polished, with setae and punctures only dorsally and ventrally along margins; metapleuron with a very short, crenulate, longitudinal sulcus running from lower margin near metacoxa through spiracle. Metapleural carina with short lamella. Propodeum with areola defined mostly by a central impression than carinae -though the posterior carinae are visible; propodeum coarsely punctured in the anterior half, with transverse striation in the apical half, the only smooth area is centrally inside the areola.

Metasoma. Mediotergite 1 barrel-shaped, wider medially than anteriorly or posteriorly; basal width/apical width 0.9× (0.8–0.9×); length/apical width 1.1×; mediotergite 1 with smooth, basal depression; apical 2/3 coarsely sculptured and with longitudinal striae, except for a median, sub-apical depressed area which is mostly smooth and a polished knob centrally in the apical margin. Mediotergite 2 transverse, trapezoidal to almost rectangular in shape; basal width/apical width 0.7×; length/apical width 0.3×; coarsely sculptured with longitudinal and transverse striae covering most of the surface, the posterior margin bordered by distinct, crenulated punctures. Mediotergite 3 about 1.5× the length of mediotergite 2 and with some sculpture centrally in the anterior margin. Mediotergite 4 and following unsculptured, polished and uniformly covered by sparse setae. Hypopygium striate, with acute tip slightly protruding beyond apical tergites. Ovipositor sheaths fully setose, 1.0× (0.9–1.1×) as long as metatibia length.

Legs. Metatibial inner spur 1.4× (1.4–1.6×) the length of outer spur, and 0.6× (0.5–0.6×) the length of metatarsomere 1. Metafemur 3.0× (3.0–3.2×) as long as wide.

Wings. Forewing vein R1a 1.0–1.1× as long as stigma length; length of R1a 6–7.0× as long as the distance between its end and the end of 3RSb. Vein r 1.0× (1.0–1.1×) the maximum width of stigma. Join of veins r and 2RS angulated and with a small knob at their junction; vein 2M 0.8× (0.7–0.9×) as long as vein (RS+M)b. Edge of vannal lobe of hindwing medially straight to convex and glabrous.

Colour: Maxillary and labial palps, tegula, two first pairs of legs (except for coxae), and basal half of metafemur yellow; head, meso and metasoma dark-brown or black; wing base and all coxae brown; metafemur, apical half of metatibia and metatarsus yellowish- brown to orange-brown. Most of veins very light brown, almost hyaline; stigma light brown.

As female except for longer flagellomere, antenna longer than body length, darker hind legs (with metafemur dark brown), and less transverse medio tergite 2 (which is almost quadrate and with striation arranged in a concentric way).