Exenterus sehuerachicus Khalaim & Ruíz-Cancino, 2015

Ruíz-Cancino, Enrique & Khalaim, Andrey I., 2015, Mexican species of the genus Exenterus Hartig (Hymenoptera: Ichneumonidae: Tryphoninae) reared from diprionid hosts, Zootaxa 4048 (1), pp. 140-150 : 145-149

Exenterus sehuerachicus Khalaim & Ruíz-Cancino , sp. nov.

( Figs 2, 4, 7–25 , 26 )

Description. Female. Fore wing length 6.6–7.1 mm (7.1 mm in holotype).

Head: Coarsely punctate, smooth and shining between punctures; punctures on face periphery and lower half of genae sparser; clypeus impunctate in lower half. Genae rounded behind eyes in dorsal view. Antenna somewhat shorter than metasoma; flagellum distinctly tapered towards apex, with 29–30 flagellomeres; basal flagellomeres elongate, mid and subapical flagellomeres subquadrate or slightly transverse. Supraclypeal suture deep and sharp. Malar space 0.4× as long as basal mandibular width. Lateral ocellus separated from face by 2.0–2.2× its own maximum diameter.

Mesosoma: Entirely densely and coarsely punctate, distance between punctures much shorter than diameter of one puncture, sometimes punctures almost touching; dull to shining between punctures (especially on scutellum and mesopleuron); scutellum centrally less densely punctate. Propodeum with posterior transverse carina distinct laterally and absent medially, with more or less distinct short longitudinal wrinkle mediodorsally; area coxalis delineated. All tarsi shortened and strongly depressed; fore and mid tarsi about 0.8 and hind tarsus 0.7–0.75× as long as their tibiae; hind tarsomere 3 transverse or as long as broad.

Metasoma: Tergite 1 of metasoma 1.1× as long as posteriorly broad, with lateromedian carinae more or less distinct in anterior 0.6–0.8 and usually indistinct posteriorly. Tergite 2 strongly transverse, 0.55× as long as posteriorly broad. Tergites 1 and 2 coarsely sculptured, punctate-reticulate (laterally) to reticulate (medially). Tergites 3+ with coarse and very dense punctures; distance between punctures much shorter than diameter of one puncture, sometimes punctures almost touching. Hypopygium apically widely rounded, sometimes weakly truncated. Ovipositor sheath in profile suboval, apically rounded.

Coloration: Head black; clypeus, face, frontal orbits, median longitudinal stripe in frons, a pair of spots on outer side of lateral ocelli, genal orbits dorsally and lower 0.5–0.7 of genae yellow. Mandible (except teeth) yellow. Antenna yellow, sometimes scape, pedicel and proximal flagellomeres infuscate or black-marked dorsally and laterally. Mesosoma with propleuron entirely yellow or with extreme hind margin blackish; pronotum yellow with dorsal and hind margins, mediodorsally and longitudinal stripe on lateral sides black; mesoscutum black with one broad stripe along anterolateral margin, and a pair of weak to rather distinct mediodorsal stripes yellow; scutellum entirely yellow or with anterior 0.2 black; postscutellum yellow; mesopleuron black with subtegular prominence and variable amount of yellow markings on anterior and lower part; mesepimeron yellow; metapleuron black, with a large yellow mark in posterior 0.5–0.8; propodeum black with a pair of conspicuous yellow posterolateral markings. Tegula yellow, sometimes brownish or blackish apically. Wings slightly infumate with yellow-brown; pterostigma pale brown. Legs yellow; fore and mid coxae sometimes black-marked dorsally; hind coxa with profuse black markings dorsally or black in dorsal half; hind femur more or less entirely brownish; hind tibia fuscous in apical about 0.3. Metasoma black; all tergites yellow-banded posteriorly and usually less conspicuously yellow-marked laterally; transverse posterior band occupies 0.15–0.2 on tergite 2 and 0.2–0.25 on tergite 3; ovipositor sheath yellow, dorsally reddish brown.

Male. Fore wing length 5.3–7.2 mm. Antenna longer than in female, with 28–32 flagellomeres; all flagellomeres distincty elongate. Lower half of epomia subparallel to anterior margin of pronotum, ending far from it; upper end of epomia weakly but distinctly curved ( Fig. 7 ). Tarsi weakly depressed and not especially short, hind tarsus almost as long as tibia. Tergite 1 of metasoma with lateromedian carinae usually quite distinct in anterior 0.8, sometimes almost reaching its posterior end. Tergites 1 and 2 coarsely sculptured, punctate-reticulate or reticulate.

Coloration: Generally darker than female. Head as in female but face with a broad black stripe medially and only lower 0.3 of genae entirey yellow. Antenna dorsally black, scape and pedicel ventrally yellow, flagellum ventrally pale brown basally to dark brown or black apically. Mesosoma black with one yellow band on anterior margin and one stripe (or spot) somewhat below dorsal margin on lateral side of pronotum, one broad stripe along lateral margin of mesoscutum, posterior about 0.7 of scutellum, postscutellum entirely, subtegular prominence and one conspicuous mark in the anterior part of mesopleuron (above upper end of epicnemal carina). Tegula yellow or brown. Wings slightly infumate with yellow-brown; pterostigma pale brown to brown. Fore and mid legs yellow, coxae dorsally black-marked, femora on posterior sides with one longitudinal dark brown or black stripe (sometimes also with one weaker stripe on anterior sides). Hind leg yellow; coxa entirely black; trochanteral segments with a black stripe dorsally; femur on lateral sides extensively brown or brownish black, sometimes femur is almost entirely dark brown with only one narrow yellow stripe dorsally; tibia in apical 0.3 fuscous; and tarsus sometimes infuscate with brown. Metasoma black with tergite 1 yellow-marked on posterolateral corners and tergites 3+ posteriorly narrowly yellow-banded.

Variation. The species is very uniform with only minor variation in structure and coloration. One female paratype possesses tergites 3 and 4 abnormally confused dorsally.

Etymology. Named after the type locality, Ejido Sehuerachi, in the state of Chihuahua.

Material examined. Holotype female (UAT), Mexico, Chihuahua, Municipio de Guachochi, Ejido Sehuerachi, Paraje Potrero del Conejo, N 27°05′31.7′′, W 107°15′29.7′′, 2385 m, ex Neodiprion autumnalis , [without date], coll. S. Robles Uribe, No. Registro 09/043N.

Paratypes. 1 ♀, 2 ♂ (1 ♀, 1 ♂ — AEIC; 1 ♂ —UAT) same data as holotype. 1 ♀, 1 ♂ ( UAEM) same data as holotype, but Paraje Bocoyna, 2372 m, N 27°05′23′′, W 107°14′45.1′′, No. Registro 09/040N.

Distribution. Mexico (Chihuahua) ( Fig. 26 ).

Biology. Reared from Neodiprion autumnalis Smith.

Comments. Similar to E. durangensis sp. nov. but differs by the shorter hind tarsus in female ( Fig. 2 ), the structure of epomia in male ( Fig. 7 ), and colour pattern in both sexes (see the key above).

Figures

FIGURE 26. Distribution map of E. durangensis sp. nov. and E. sehuerachicus sp. nov.

FIGURES 1 – 7. Exenterus durangensis sp. nov., ♀ (1, 3) and ♂ (5, 6): 1 — hind tarsus, dorsal; 3 — base of metasoma, dorsal; 5 — head, lateral; 6 — pronotum, lateral. Exenterus sehuerachicus sp. nov., ♀ (2, 4) and ♂ (7): 2 — hind tarsus, dorsal; 4 — base of metasoma, dorsal; 7 — pronotum, lateral.

FIGURES 8 – 13. Exenterus sehuerachicus sp. nov., ♀, holotype (8, 10 – 13) and paratype (9): 8, 9 — antenna, lateral; 10 — head and mesosoma, lateral; 11 — head, lateral; 12 — head and mesosoma, dorsal; 13 — propodeum, dorsal.

FIGURES 14 – 20. Exenterus sehuerachicus sp. nov., ♀, holotype (15, 18, 19) and paratype (14, 16, 17, 20): 14 — body, lateral; 15 — apex of fore wing; 16, 18 — hind tibia and tarsus, lateral; 17 — hind tarsus, ventral; 19 — hind tarsus, dorsal; 20 — metasoma, dorsal.

FIGURES 21 – 25. Exenterus sehuerachicus sp. nov., ♂, paratype: 21 — head, front; 22 — head and mesosoma, lateral; 23 — propodeum, dorso-postero-lateral; 24 — metasoma, lateral; 25 — hind leg (without coxa), lateral.