Monoctonus brachyradius Čkrkić & Petrović & Kocić & Kavallieratos & Hebert & Tomanović 2019, sp. n.

Monoctonus brachyradius Čkrkić, Petrović & Tomanović, sp. n.

Holotype. Female. Canada, Quebec, Mingan Archipelago National Park Reserve, Quarry Island, 12 IX 2013, coll. Park staff, Malaise trap. Holotype slide mounted and deposited in CNC. Paratypes. Canada, Quebec, Mingan Archipelago National Park Reserve, Quarry Island, 20 VIII 2013, 1 female; 18 IX 2013, 3 males. Paratypes slide mounted and deposited in FBUB. (Fig. 2 a–h)

Diagnosis. Monoctonus brachyradius resembles M. nervosus based on the number of flagellomeres, fore wing venation, and shape of ovipositor sheath, but it can be differentiated by a distinctly shorter distal abscissa of R1 (length of pterostigma/R1 length is 4.8–5.1 in M. brachyradius and 1.8–2.3 in M. nervosus).

Female. Head (Fig. 2a). Eyes oval, medium sized, sparsely setose. Malar space equal to 0.14 of longitudinal eye diameter. Tentorial index 0.13. Clypeus oval with 6 long setae. Maxillary palps with four palpomeres, labial palps with three palpomeres. Antenna with 15 antennomeres, filiform, setae on flagellomeres semierect, subequal to flagellomere diameter (Fig. 2b). Flagellomere 1 (F1) 4.5× as long as wide, without longitudinal placodes. F2 3.3× as long as wide, with 1–2 longitudinal placodes (Fig. 2c). F3, F4 and F5 with 2, 3–4 and 1–3 longitudinal placodes, respectively. F1 1.1× longer than F2.

Mesosoma. Mesoscutum with incomplete notaulices, visible only in anterior part. Dorsal surface of mesoscutum smooth, without setae (Fig. 2d). Head width/mesoscutum width ratio 1.45. Propodeum areolated with clearly defined narrow central pentagonal areola (Fig. 2e).

Fore wing (Fig. 2h). Wing length 2 mm, width 0.8 mm. Stigma narrow, 7.5× as long as wide and 4.9× as long as distal abscissa of R1. Vein m-cu distinct, 2RS effaced near m-cu. Veins r and 3RS distinct.

Metasoma. Petiole 2.1× as long as wide at spiracles. Spiracular tubercles prominent. Dorsal disc of petiole moderately rugose in basal third, with one irregular carina in upper two thirds medially and with 9–10 long setae on each side (Fig. 2f). Ovipositor sheath ploughshare shaped. Ovipositor sheath length/width ratio 3 (Fig. 2g).

Colour. Head brownish-black, eyes black. Face with mouthparts and clypeus yellowish-brown. F1 yellow, except for the apical ¼ which is brown, remainder of antenna brown. Mesonotum and propodeum brown, legs light brown. Wings hyaline with brown venation. Petiole and rest of metasoma brown, ovipositor sheath yellowishbrown. Body length 2.3 mm.

Male. Head. Eyes oval, medium sized, sparsely setose. Malar space equal to 0.42 of longitudinal eye diameter. Tentorial index 0.4. Clypeus oval with 6–7 long setae. Maxillary palps with four palpomeres, labial palps with three palpomeres. Antenna with 18 antennomeres, filiform, setae on flagellomeres semierect, subequal to flagellomere diameter. Flagellomere 1 (F1) 2.2× as long as wide, with 6 longitudinal placodes. F2 2.2× as long as wide, with 5 longitudinal placodes. F3, F4 and F5 with 5, 6 and 5 longitudinal placodes, respectively. F1 length equal to F2.

Mesosoma. Mesoscutum without notaulices, with two longitudinal rows of setae on dorsal surface. Head width/ mesoscutum width ratio 1. Propodeum areolated with clearly defined narrow central pentagonal areola.

Fore wing. Wing length 2.1 mm, width 0.9 mm. Stigma narrow, 5.8× as long as wide and 4.7× as long as distal abscissa of R1. Vein m-cu distinct, 2RS effaced near m-cu. Veins r and 3RS distinct.

Metasoma. Petiole 1.7× as long as wide at spiracles. Spiracular tubercles prominent. Dorsal disc of petiole moderately rugose in basal third, with one irregular carina in upper two thirds medially and with 4–5 long setae on each side.

Colour. Head brown, mouthparts yellowish-brown, antenna brown. Mesonotum and propodeum brown, legs light brown. Wings hyaline with brown venation. Petiole and rest of metasoma brown. Body length 2.1 mm.

Host: unknown.

Distribution. Eastern Canada.

Etymology: The name of the new species refers to the very short distal abscissa of R1.