Orthocentrus minor, Humala, 2019

Humala, Andrei E., 2019, Mexican species of the genus Orthocentrus (Hymenoptera, Ichneumonidae: Orthocentrinae), Zootaxa 4709 (1), pp. 1-83 : 48-49

Orthocentrus minor sp. nov.

( Figs 7 E , 12 E , 15 E , 18 E , 29 )

Material examined. Holotype ♀: México, Tamaulipas, Gómez Farias, Los Cedros , 300 m; MT, 13.III.2003, leg. D. Kasparyan ( UAT).

Description. Female. Fore wing length 2.3 mm.

Face medially 0.9 × wider than high; face and head between eyes at ocelli papillate; eyes setose, inner orbits divergent ventrally; dorsal ridge of face inbetween antennal sockets without a median prominence; face in profile slightly rounded, edge of clypeus slightly impressed medially, antennal sockets on a shelf but shelf not particularly high (Hw/Fp = 5.8); subocular sulcus distinct, sharp, bent towards occiput; maxillary palp reaching to about epicnemial carina. In dorsal view, head posteriorly moderately concave, temples distinct but quite narrow, about 0.2 × eye width, posterior ocellus separated from eye by 0.6 × ocellar diameter, anterior ocellus separated from eye by 1.4 × ocellar diameter, ocellar-ocular grooves present. Minimum distance between antennal sockets about third of diameter of socket, antenna slender, with 24 quadrate to slightly elongate flagellomeres, flagellomeres not gradually shortening towards apex, basal flagellomere 1.0 × as long as wide and about 1/3 of the length of scape, scape parallel-sided.

Mesosoma smooth and polished except pronotum with short striations postero-ventrally and propodeum dorsally sometimes with coriaceous microsculpture; mesoscutum lacking notauli; in profile, scutellum not particularly high, metapleuron slightly convex; propodeum with posterior transverse carina present between lateral longitudinal carinae, median longitudinal carinae complete, and lateral longitudinal carinae present as stubs hardly reaching spiracles; spiracles small.

Legs broad; coxae and femora polished, tibiae and tarsi coriaceous-granulate; hind coxa 1.2 × as long as first tergite, hind femur 2.9 × as long as high, hind tibia 3.4 × as long as apically wide; tibiae with spine-like setae.

Wings not particularly narrow; fore wing with areolet open, pterostigma nearly symmetrical; vein Rs straight; hind wing with nervellus not intercepted.

First tergite elongate, very slightly widening apically, 1.3 × as long as apically wide; coriaceous with some striae, with two posteriorly almost complete median longitudinal carinae, with transverse impressions originating at about middle of tergite, sloping posteriorly, not meeting centrally. Second tergite 0.75 × as long as apically wide; coriaceous-strigose, with transverse impressions originating at middle of tergite, sloping posteriorly, not meeting centrally; basal thyridia rectangular/oval, second thyridia roundish raised areas at about middle of tergite; third tergite coriaceous basally. Remaining tergites smooth and polished. Ovipositor hidden; ovipositor sheath with sparse setae.

Body largely setose except pronotum, mesopleuron and metapleuron; setae very scattered on propodeum and posterior sides of coxae.

Head yellow except frons, flagellomeres in apical half of flagellum, temples partly, interocellar area connected with occiput dorsally, brown, inner orbits from about antennal sockets to posterior ocelli yellowish, mouthparts creamy; mesosoma brown except propleuron, pronotum ventrally and in dorso-posterior corner and lower half of mesopleuron, yellow; mesoscutum anteriorly and near expected locations of notauli reddish-brown; metasoma brown to dark brown except sternites creamy; fore and mid coxae, trochanters and trochantelli creamy white, rest of fore and mid legs light yellow with some brown on dorsal sides, hind legs yellow with dorsal side and a brown patch anteroapically of coxa brown; hind tibia infuscate dorsoapically with narrow brown basal ring.

Male. Unknown.

Biology. Hosts unknown. Specimen was collected from wet tropical forest.

Distribution. Mexico (Tamaulipas).

Etymology. Named after the small size.

Comments. Compared with the other species that have completely papillate face, antennal sockets usually on a distinct but low shelf, setose eyes and second tergite with a posterior transverse groove, pterostigma nearly symmetrical, unlike in O. pictus , O. veracruzus and O. wahlbergi ; mesoscutum with ‘shoulder stripes’ along notaular lines and frontal orbits light brown and indistinct, unlike in O. nicaraguensis .

Figures

FIGURE 7. Lateral views: Orthocentrus wahlbergi species-group (in part).A: aztecus, B: collaris, C: contrerasi, D: mexicanus, E: minor, F: oaxacae. Scale 1.0 mm.

FIGURE 12. Faces: Orthocentrus wahlbergi and O. insularis species-groups. A: aztecus, B: collaris, C: contrerasi, D: mexicanus, E: minor, F: oaxacae, G: pictus, H: podagricus, I: scabrosus, J: tamaulipecus, K: veracruzus, L: ruizi. Scale 0.2 mm.

FIGURE 15. Heads in dorsal view: Orthocentrus wahlbergi and O. insularis species-groups. A: aztecus, B: collaris, C: contrerasi, D: mexicanus, E: minor, F: oaxacae, G: pictus, H: podagricus, I: scabrosus, J: tamaulipecus, K: veracruzus, L: ruizi. Scale 0.2 mm.

FIGURE 18. Basal tergites: Orthocentrus wahlbergi and O. insularis species-groups. A: aztecus, B: collaris, C: contrerasi, D: mexicanus, E: minor, F: oaxacae, G: pictus, H: podagricus, I: scabrosus, J: tamaulipecus, K: veracruzus, L: ruizi. Scale 0.2 mm. Metasoma dorso-lateral view: M: Orthocentrus tergalis. Scale 0.5 mm.

FIGURE 29. Distribution map of Orthocentrus in Mexico. O. collaris, O. nicaraguensis, O. minor, O. oaxacae