Lamachus nigrus Li, Sheng & Sun

Li, Tao, Sheng, Mao-Ling & Sun, Shu-Ping, 2012, Species of the genus Lamachus Foerster (Hymenoptera, Ichneumonidae) parasitizing diprionid sawflies (Hymenoptera, Diprionidae) with descriptions of two new species and a key to Chinese species, ZooKeys 249, pp. 37-49 : 38-39

Lamachus nigrus Li, Sheng & Sun sp. n. Figures 1-6

Etymology.

The specific name is derived from the body being entirely black.

Types.

Holotype, female, CHINA: Weining, Guizhou Province, 13 March 2012, leg. Tao Li, Mao-Ling Sheng. Paratypes: 7 females and 5 males, CHINA: Weining, Guizhou Province, 8 to 24 March 2012, leg. Tao Li, Mao-Ling Sheng.

Diagnosis.

Malar space 0.4 to 0.5 times as long as basal width of mandible. Postocellar line approximately 1.5 to 1.6 times as long as ocular-ocellar line. Antenna with 39 to 40 flagellomeres. Fore wing with vein 1cu-a distal of 1/M by about 0.5 times length of 1cu-a. Vein 2-Cu approximately 1.5 times as long as 2cu-a. Hind wing vein 1-cu about 1.5 times as long as cu-a. First tergum 1.4 times as long as apical width. Abdomen entirely black.

Description.

Female (Fig. 1). Body length 8.0 to 10.0 mm. Fore wing length 7.5 to 9.0 mm.

Head. Inner eye orbits weakly concave at level of antennal insertions. Face (Fig. 2) 1.6 to 1.7 times as wide as long, with dense punctures, upper center margin with weak longitudinal wrinkles. Clypeus approximately flat and smooth, with sparse setae, 2.0 times as wide as long; central part of apical margin distinctly concave. Mandible smooth, with weak punctures, upper tooth slightly longer than lower tooth. Malar space with fine leathery texture, 0.4 to 0.5 times as long as basal width of mandible. Gena with evenly dense punctures. Posterior part of vertex (Fig. 3) with texture as that of gena. Ocellar triangle with fine leathery texture, with weak median longitudinal groove. Postocellar line about 1.5 to 1.6 times as long as ocular-ocellar line. Frons approximately flat, with texture as that of face, lower portion concave at antennal areas. Antenna with 39 to 40 flagellomeres, ratio of length from first to fifth flagellomeres: 9.0:5.0:4.5:4.5:4.0. Occipital carina complete.

Mesosoma. Anterior portion of pronotum with fine leathery texture and dense punctures; median portion with short transverse wrinkles; upper posterior portion with dense punctures. Mesoscutum evenly convex, with texture as that of upper posterior portion of pronotum. Notaulus evident on anterior half of mesoscutum. Scutoscutellar groove wide, with weak longitudinal wrinkles. Scutellum evenly convex, with sparse punctures, larger than those of mesoscutum. Postscutellum transverse, punctures denser than on scutellum. Mesopleuron (Fig. 5) evenly convex, with punctures as scutellum. Epicnemial carina weak, 0.5 times as long as mesopleuron. Speculum with fine leathery texture. Metapleuron convex, with dense punctures and fine wrinkles. Submetapleural carinae complete. All tibiae with distinct pegs. Ratio of length of hind tarsomeres 1:2:3:4:5 is 25.0:11.0:7.0:4.0:6.0. Fore wing with vein 1cu-a distal of 1/M by about 0.5 times length of 1cu-a. Vein 2-Cu approximately 1.5 times as long as 2cu-a. Fore wing with stalked triangular areolet. Vein 3rs-m distinctly longer than 2rs-m. Areolet receiving vein 2m-cu approximately at lower-posterior angle. Hind wing vein 1-cu about 1.5 times as long as cu-a. Propodeum (Fig. 4) evenly convex, without areas, with texture as that of mesoscutum. Pleural carina distinct. Propodeal spiracle approximately circular, located at anterior 0.3 of propodeum.

Metasoma. First tergum 1.4 times as long as apical width, with fine granulose texture. Basal portion of median dorsal carinae present. Spiracle circular, at middle of first tergum. Second tergum (Fig. 6) approximately 0.6 times as long as apical width, with texture as that of first tergum. Thyridium present. Third tergum (Fig. 6) and following terga slightly compressed, with fine leathery texture and dense small punctures. Ovipositor sheath approximately 0.3 times apical depth of metasoma. Ovipositor with dorsal notch. Basal portion of ovipositor very wide, apically portion distinctly slender.

Color (Fig. 1). Black, except the following. Median portion of face, clypeus, mandible except black teeth, ventral portion of fore coxa, median portion of subalar ridge, hind corner of pronotum, lateral and apical portions of scutellum, postscutellum, yellow. Maxillary and labial palpi blackish brown. Anterior portion of fore femur, tibia, tarsomeres, basal half of mid tibia, yellowish brown. Apical portion of mid tibia and tarsus blackish brown. Wing membrane brownish hyaline. Pterostigma and veins brownish black.

Male. Body length about 7.0 to 9.0 mm. Fore wing length about 6.0 to 7.0 mm. Antenna with 37 to 39 flagellomeres. Median and lower lateral portions of face, clypeus, mandible (teeth black), maxillary palp, anterior portion of fore coxa, hind corner of pronotum, subalar ridge, basal portion of notaulus, lateral fleck of scutellum, postscutellum, yellow. Labial palp, pterostigma, veins, blackish brown. Fore (except median portion of tibia blackish brown, first to fourth tarsomeres yellowish brown) and mid legs dark brown.

Host.

Neodiprion huizeensis Xiao & Zhou ( Hymenoptera : Diprionidae ).

Host plant.

Pinus armandi Franch. ( Pinaceae ).

Biology.

The mature larva forms a cocoon inside host’s cocoon and outside the body of the host larva.

Remarks.

This new species is similar to Lamachus gilpiniae but can be distinguished from the latter by the following combination of characters: upper tooth of mandible longer than lower tooth; postocellar line approximately 1.5 to 1.6 times as long as ocular-ocellar line; median longitudinal carina of propodeum absent; first tergum 1.4 times as long as apical width; second tergum 0.6 times as long as apical width. Lamachus gilpiniae : upper tooth of mandible as long as lower tooth; postocellar line approximately as long as ocular-ocellar line; median longitudinal carina of propodeum distinct; first tergum 1.7 times as long as apical width; second tergum 0.7 to 0.8 times as long as apical width.