Eurytenes pachycephalus Walker & Wharton, 2011

Walker, Andrea K. & Wharton, Robert A., 2011, A review of New World Eurytenes s. str. (Hymenoptera, Braconidae, Opiinae), Journal of Hymenoptera Research 20, pp. 23-46 : 36-38

Eurytenes pachycephalus Walker & Wharton sp. n. Fig. 6 26-29

Holotype

♀ (TAMU): Mexico: Michoacan 6 mi. N. Cheran 8-VII-1985 Woolley & Zolnerowich [four lines on a single label].

Paratypes

(TAMU): 10 ♂, same data as holotype except eight with date 7-8.vii.1985.

Diagnosis.

This species is most readily recognized by its broad clypeus and inflated gena. It is a much larger species than Eurytenes ormenus , which was also collected at high elevation sites in central Mexico. Although both Eurytenes pachycephalus and Eurytenes ormenus have a uniformly dark petiole, the hind femur is dark in Eurytenes ormenus and more lightly colored in Eurytenes pachycephalus .

Description

(♀). Length of body: 2.9 mm, length of fore wing 3.3 mm.

Head.36 flagellomeres; first, fifteenth, and fifth from last flagellomere length 3.3, 2.3, 2.3 × width, respectively. Face 2.0 × wider than high. Clypeus broad, semi-elliptical, with ventral margin truncate, 2.9 × wider than high; 2.1 × wider than distance between clypeus and eye. Mandible gradually expanded basally, without distinct basal tooth or swelling. Gena broad ( Fig. 28 ). Occipital carina extending about 0.5 × distance from eye to nearest lateral ocellus.

Mesosoma. Posterior-ventral margin of lateral pronotum strigose for most of length, the sculpture extending towards middle of sclerite. Precoxal sulcus extending very close to anterior margin of mesopleuron; deeply crenulate anteriorly, sculptured area broadening posteriorly; precoxal sulcus approximately 45 degrees, inclined slightly more vertically than Eurytenes abnormis. Notaulus distinctly impressed and crenulate over anterior 0.3-0.4 of mesoscutal disc; with cluster of short setae at rugulose base of anterior declivity extending ventrally to some extent onto anterior declivity at each side; longer setae absent posteriorly. Median carina extending over anterior 0.2 before bifurcating to form five-sided areola; surface of areola and lateral margin of propodeum rugose, posterior-lateral fields and region anteriorad areola smooth or nearly so.

Wings. Fore wing r-m very weakly pigmented at extreme base, largely spectral (with lateral boundaries indistinct); m-cu distinctly postfurcal; 3M distinctly pigmented and largely tubular in basal third, gradually weakening distally. Hind wing m-cu extending nearly half way to wing margin as a very weakly pigmented and impressed curved line.

Legs. Hind tibia 8.3 × longer than maximum width.

Metasoma.Petiole 2.1 × longer than apical width. Female ovipositor sheath barely visible due to postmortem changes in position; visible portion densely setose.

Color. Head, mesosoma, and petiole black. Scape and pedicel yellow, flagellomeres dark brown; mandible butterscotch with distal tip infuscated; clypeus dark brown dorsally, ventral half butterscotch; palps and tegula butterscotch. Metasoma with T2 and T3 brown, middle tergites with brown and yellow transverse banding, apical tergites yellow. Legs yellow except hind tibia butterscotch to weakly infuscate, tarsus entirely medium brown. Wings largely hyaline, though appearing very slightly darker than other species treated here.

Male. Same as female except length of body 2.9-3.1 mm (m=3.0), length of fore wing 3.1-3.7 (m=3.4). Antenna with 34-38 flagellomeres; first flagellomere length 2.3 -3.0 × width (m=2.8), fifteenth flagellomere length 2.0-2.35 × width (m=2.25), fifth from last flagellomere length 1.8-2.2 × width (m=2.1). Face 1.9-2.1 (m=2) × wider than high. Clypeus 1.7-3.0 (m=2.3) × wider than distance between clypeus and eye. Precoxal sulcus shape variable, generally narrowing anteriorly and widening ventral-posteriorly. 1-3 longer, somewhat decumbent setae extending posteriorly from notaulus on mesoscutal disc. Fore wing r-m mostly unpigmented, usually tubular throughout (with lateral boundaries distinct). Hind wing m-cu usually extending more than half way to wing margin as a weakly pigmented, spectral impression. Hind tibia 7.4-8.5 (m=7.9) × longer than maximum width. Petiole 2.1-2.7 (m=2.35) × longer than apical width.

Head and petiole dark reddish-brown to black; hind tibia usually more distinctly brown; tergites butterscotch with transverse bands of medium brown on T2-T4 and uniformly medium brown on T5 and following.

Etymology.

The name pachycephalus is derived from Greek: pachy, fat; cephalus, head. The name refers to the larger size of the head, extended gena and broad clypeus of this species.

Host.

Unknown.

Distribution.

Central Mexico.

Comments.

We have selected the lone female as the holotype, for ease in comparison with the other species described here, even though the female specimen is not in the best of condition. The hind legs of this species are shorter and broader than those of Eurytenes ormenus .

Figures

Figures 4 - 7. Eurytenes spp., habitus. 4 Eurytenes abnormis, female 5 Eurytenes ormenus sp. n., female 6 Eurytenes pachycephalus sp. n., male 7 Eurytenes dichromus sp. n., female.

Figures 26 - 29. Eurytenes pachycephalus sp. n. 26 Face 27 Mesosoma, lateral view, arrow = precoxal sulcus 28 Head, lateral view 29 Petiole, dorsal view.