Exenterus durangensis 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 : 143-145

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

( Figs 1, 3, 5, 6 , 26 )

Description. Female. Fore wing length 7.1–8.5 mm (8.5 mm in holotype).

Head: Coarsely punctate, smooth and shining between punctures; punctures on lower half of genae slightly sparser; clypeus impunctate in lower half. Genae rounded behind eyes in dorsal view. Antenna somewhat shorter than metasoma; flagellum distinctly tapered towards apex, with 27–29 flagellomeres; a few basal flagellomeres elongate, mid and subapical flagellomeres subquadrate or transverse. Supraclypeal suture deep and sharp. Malar space 0.35× as long as basal mandibular width. Lateral ocellus separated from face by 1.8–2.0× 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 or vestigial medially, without longitudinal wrinkle mediodorsally; area coxalis usually delineated. All tarsi shortened and strongly depressed; fore and mid tarsi 0.8–0.9× and hind tarsus 0.8–0.85× as long as their tibiae; hind tarsomere 3 distinctly elongate.

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

Coloration: Clypeus, face and genae yellow. Frons and vertex black with yellow frontal orbits (extending above to lateral ocelli), broad median longitudinal stripe, a pair of small spots before lateral ocelli and a pair of larger markings behind lateral ocelli. Mandible (except teeth) yellow. Antenna yellow; scape, pedicel and flagellomere 1 basally black-marked dorsally. Mesosoma with propleuron and pronotum entirely yellow; mesoscutum black with lateral margins and a pair of weak or distinct narrow mediodorsal stripes yellow; scutellum entirely yellow or (in holotype) with anterior margin narrowly black; postscutellum yellow; mesopleuron predominantly yellow with variable amount of black in posterior upper quarter, and black mark extending below subtegular prominence towards anterior margin of mesopleuron; mesepimeron yellow; metapleuron 80% or more yellow, narrowly black on upper and anterior margins and upper anterior corner black; propodeum black with a pair of large yellow posterolateral markings. Wings slightly infumate with yellow-brown. Tegula entirely yellow. Pterostigma pale brown. Legs yellow; hind leg with coxa with small black markings dorsally and on lateral sides, trochanteral segments black-marked dorsally and tibia fuscous in apical 0.3–0.5. Metasoma black; all tergites yellow-banded posteriorly and laterally, tergite 1 sometimes also with yellow stripes on lateromedian carinae basally; yellow posterior bands on tergites 1 and 2 narrow medially and much broader laterally, thus the margin between black and yellow parts is strongly arcuate; transverse posterior band occupies 0.2–0.3 on tergite 2 and about 0.5 on tergite 3; yellow bands on tergites 4+ occupy more than half (anterior black part often largely covered by preceding tergite, and therefore tergites seeming almost entirely yellow); ovipositor sheath yellow, sometimes infuscate.

Male. Fore wing length 7.3–8.3 mm. Antenna longer than in female, with 30–32 flagellomeres; all flagellomeres distincty elongate. Epomia almost straight, distinctly converging towards anterior margin of pronotum ventrally and more or less reaching it ( Fig. 6 ). Tarsi weakly depressed, longer than in female; hind tarsus 0.9× as long as tibia. Tergite 1 of metasoma with lateromedian carinae distinct in anterior half and usually indistinct posteriorly. Tergites 1 and 2 coarsely sculptured, punctate-reticulate or reticulate.

Coloration: Much darker than female. Head predominantly black; face yellow with median longitudinal black stripe; frontal orbits, narrow median longitudinal stripe on frons and narrow genal orbits yellow. Antenna with scape and pedicel predominantly black, ventrally yellow; flagellum entirely black. Mesosoma black with only subtegular prominence and hind margins of scutellum and postscutelum yellow. Tegula black. Wings very slightly infumate with yellow-brown. Pterostigma pale brown. Fore and mid coxae and first trochanter black, sometimes yellow-marked ventrally; second trochanters yellow, legs with sometimes black-marked dorsally; femora and tibiae predominantly brownish black, more or less yellow on ventral and anterior sides yellow; tarsi fuscous dorsally and yellowish ventrally. Hind leg with coxa and trochanteral segments black (second trochanter sometimes with small yellow marking ventrally); femur brownish black to black; tibia dark brown basally to black apically, yellow on ventral side in basal about 0.7; and tarsus brownish black, slightly paler ventrally. Metasoma black, tergites 3+ medially with posterior margin narrowly yellow.

Etymology. Named after the type locality, the state of Durango, Mexico.

Material examined. Holotype female (UAT), Mexico, Durango, San Dimas, Ejido Los Negros, parasitoid of Zadiprion falsus , 9.X.1989, coll. R. Miranda.

Paratypes. 1 ♀, 1 ♂ ( AEIC) same data as holotype. 1 ♀, 2 ♂ (UAT) same data, but 25–26.X.1989, coll. R. Miranda & S. Salazar.

Distribution. Mexico (Durango) ( Fig. 26 ).

Biology. Reared from Zadiprion falsus Smith.

Comments. Similar to E. sehuerachicus sp. nov. but differs by the longer hind tarsus in female ( Fig. 1 ), the structure of epomia in male ( Fig. 6 ), 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.