Rhorus lannae Reshchikov & Xu, 2017

Reshchikov, Alexey, Choi, Jin-Kyung, Xu, Zai-fu & Pang, Hong, 2017, Two new species of the genus Rhorus Foerster, 1869 from Thailand (Hymenoptera, Ichneumonidae), Journal of Hymenoptera Research 54, pp. 79-92 : 84-87

Rhorus lannae Reshchikov & Xu sp. n. Figs 1 , 11 , 12-19

Material examined.

Holotype, male, THAILAND: Chiang Mai, Huai Nam Dang National Park , guest house, 19°18.803'N 98°36.395'E, Malaise trap, 21-28.ix.2007, T5507, leg. Anuchart & Thawachai (QSBG) ; Paratypes: 1 male, THAILAND, Chiang Mai, Huai Nam Dang National Park , guest house, 19°18.803'N 98°36.395'E, Malaise trap, 21-28.ix.2007, T5507, leg. Anuchart & Thawachai, (QSBG) ; 1 male, THAILAND: Chiang Mai, Huai Nam Dang National Park , guest house, 19°18.803'N 98°36.395'E, Malaise trap, 7-14.ix.2007, T5512, leg. Anuchart & Thawachai ( CNC) .

Diagnosis.

This species differs from other Oriental species by combination of the following characteristics: lobe of oral carina strongly elevated behind mandibles (Fig. 19 ); areolet petiolate; costula present (Fig. 19 ). This new species is similar to the trans-Palaearctic Rhorus longicornis Holmgren, but can be separated from the latter by: mesoscutum coarsely punctate (very finely in Rhorus longicornis ), lobe of oral carina strongly elevated (moderately in Rhorus longicornis ), mandible yellow and mesoscutellum with yellowish marking in male (always blackish in Rhorus longicornis ).

Description.

Male (holotype) (Fig. 11 ). Body length 10.0 mm. Fore wing length 7.0 mm. Flagellum with 41 flagellomeres, about as long as fore wing; two basal flagellomeres 0.8 × as long as maximum diameter of eye; first flagellomere 3.5 × as long as apical width. Head not narrowed posteriorly (Fig. 15 ); temple length in middle 0.9 × transverse diameter of eye; cheek convex below eye; temples smooth. Face slightly widened ventrally, without central bulge (Fig. 12 ); face rather rugose and coarsely and densely punctate; average distance between punctures about 0.9 × their diameter. Frons with weakly defined longitudinal carina, with weak striae in anterior part and distinct fine punctures in posterior part. Clypeus rather rugose, not separated from face (Fig. 12 ); its lower margin distinctly truncate. Malar space 0.6 × as long as basal width of mandible. Upper tooth distinctly shorter than lower tooth (Fig. 12 ); mandible not swollen before base, slightly rugose, impunctate, with a defined transverse depression at base. Lobe of oral carina strongly elevated behind mandibles (Fig. 19 ).

Pronotum coarsely and densely punctate, with distinct epomia (Fig. 19 ). Mesoscutum coarsely and densely punctate (Fig. 14 ). Mesopleuron (except for speculum) densely punctate (Fig. 19 ); speculum large, covering about 0.6 × length of mesopleuron, with polished part below mesopleural pit extending to hind corner of mesopleuron. Mesoscutellum rather finely punctate (Fig. 14 ). Metapleuron finely punctate. Propodeum shining, finely punctate, with long, dense white setae; basal area fused with area superomedia, U-shaped; costulae present; apical area as long as basal area and area superomedia combined, with distinct longitudinal carina (Fig. 13 ). Pterostigma 6.0 × as long as broad (Fig. 18 ). Areolet petiolate (Fig. 19 ). Fore wing with cu-a postfurcal. Hind wing with Cu1 intercepted below middle. Fore claw with 9 teeth. Hind femur 3.5 × as long as broad; length proportion of hind tarsomeres 1-5 = 4:2:1.7:1:2:1.3; hind claw with 5 teeth.

T 1 3.5 × as long as apical width; its longitudinal carinae extending to 0.6 × its length; space between carinae smooth, without punctures; dorso-lateral carinae obliterated beyond spiracles. T1 (behind spiracles) and T2 completely smooth and more or less evenly and finely puncate; average distance between punctures 1.0-1.5 × their diameter (Fig. 17 ). Last sternite elongate. Parameres broad basally.

Color. Head, mesosoma, coxae, trochanters, most of fore and mid femora dorsally, hind femur, apical part of hind tibia, hind tarsus, basal part of T1, apical part of T5 and following tergites black (Figs 16 , 17 ). Antenna with flagellum dark brown, scape and basal flagellomeres ventrally yellowish (Fig. 12 ). Mandible yellow, with teeth blackish-brown (Fig. 12 ). Face entirely yellow (Fig. 12 ). Apical margin of clypeus and area around tentorial pits black (Fig. 12 ). Mesosoma black (Figs 14 , 19 ), with posterior half of mesoscutellum yellowish-brown (Fig. 14 ). Tegula and subtegular ridge of mesopleuron black (Fig. 19 ). Pterostigma black (Fig. 18 ). Ventral part of fore and mid femora, apical part of hind femur, fore and mid tibiae and tarsi, hind tibia (except apical part), apical part of T1, T2-T4, and apical part of T5 reddish-brown (Figs 16 , 17 ).

Female. Unknown.

Distribution.

Thailand.

Etymology.

The species name " lannae " is derived from a combination of " lanna ", the Latin word for “lobe”, reflecting the strongly defined short and high lobe of the oral carina, elevated behind the mandibles, and the Thai word “อาณาจักรล้านนา”, the Lan Na, "Kingdom of a Million Rice Fields", a medieval state in Northern Thailand.

Figures

Figure 1. Landscape and type habitat of Rhorus lannae Reshchikov & Xu, sp. n., Huai Nam Dang National Park, Chiang Mai Province, Thailand, photographer Buddhaphong Wongsanont.

Figure 11. Rhorus lannae Reshchikov & Xu, sp. n., male paratype, habitus in lateral view.

Figures 12 - 19. Rhorus lannae Reshchikov & Xu, sp. n., male paratype. 12 Head in frontal view 13 Propodeum in dorsal view 14 Mesosoma in dorsal view 15 Head in dorsal view 16 Metasoma in lateral view 17 Metasoma in dorsal view 18 Wings 19 Head and mesosoma in lateral view.