Epigomphus wagneri new species

Figures 1 d; 3c; 4c; 5e, f; 9c; 10c; 12.

Specimens examined. Holotype male: COSTA RICA, Provincia Puntarenas, Monteverde, Río Guacimal (10.27, - 84.82), 725 m, 27 June 2010, leg. WAH (INBIO; INB 0004319188).

Etymology. This species is named for David Wagner, a brilliant entomologist, naturalist, and gomphid enthusiast, who roused my passion for the Odonata, and who has proven to be a trusted friend and travel companion on many expeditions in Costa Rica and Ecuador.

Description. Male holotype. Head with maximum width 7.0 mm (Fig. 1 d), dark brown above; labrum with a pair of large pale spots near lateral margins; base of mandible and gena pale; top of frons with a pale stripe covering anterior 2/3, indented in middle but unbroken; antennae all dark; eyes blue in life; lateral ocelli slightly closer to eye margin than to center line; postocellar area with only a shallow central depression; posterior margin of occiput with a rounded ridge, the ridge bearing a pair of collapsed small tubercles on dorsum; rear margin of ridge weakly indented in dorsal view; underside of head pale in anterior half, shading to dark in posterior half.

Thorax dark brown with a pattern of pale markings similar to E. subobtusus (Fig. 1 d; 9c). Prothorax fore lobe with pale anterior margin; midlobe with a pair of contiguous pale spots in center and a pale spot on each side; hind lobe dark; propleuron pale on lower margin. Pterothorax with mesepisternum bearing two complete pale antehumeral stripes, both separate from collar stripe; mesepimeron with a complete pale stripe in center; metepisternum with a broad stripe that narrows posteriorly and ends almost separated from a posterior spot; metepimeron mostly pale bordered above by brown and with a thick central brown stripe about 2/3 as long as the segment; mesinfraepisternum with a pale spot at upper end and a larger pale triangle at lower end; metinfraepisternum all pale; metasternum pale; underside pale, unmarked. Legs. Fore and mid legs with femur mostly black, shading to brown at base and to lighter brown on posterior side; interior side of foreleg pale; hind femur light brown, shading to dark brown at apex. Wings hyaline (Fig. 3 c) with brown to black venation; basal subcostal veins present; cubito-anal crossveins 3 in all wings; FW Ax 18, 17 with 6, 6 thickened; Px 13, 14; HW Ax 13, 14 with 6, 7 thickened; Px 13, 13; pterostigma dark red-brown, opaque, 3.3 mm in FW, 3.6 mm in HW; crossveins above supratriangle between arculus and point of branching of RP 6, 6 in FW, 4, 4 in HW; posttriangular cell space in FW with two rows of cells for 9, 8 cells.

Abdomen dark brown with pale markings; S1–4 with a pale dorsal mid line (wider on S1–2); S1–2 mostly pale on sides, S3 with a pale lateral stripe 3/4 length of segment; S4–6 with a basal pale triangle on sides; S7 2 /3 pale; S8–10 and appendages unmarked; S10 with a low dorsal hump barely grooved on mid line.

Abdominal appendages. Cercus (Fig. 4 c; 10c) 2.2 mm long, shaped as in E. subobtusus; distal transverse edge with 7 small teeth; epiproct forming a thick fused plate with short branches and a short, broad U-shaped sinus; in lateral view a hump at mid length where branches curve downward, then directed rearward to an abrupt dull acute apex; in ventral view the sinus indented at two levels (Fig. 4 c).

Secondary genitalia. Vesica spermalis (Fig. 5 e, f) similar to other Costa Rican species in having a ventral protuberance on the dorsal lobe, but differs from others in that the horns are pointed vertically as in E. camelus (Fig. 11 g) and E. quadracies (Calvert 1903) (Fig. 11 h), while those of other Costa Rican species are directed rearward.

Measurements (mm). Total length 47; abdomen 36; FW 33; HW 31, maximum width 8.0.

Female. Unknown.

Diagnosis. Thoracic pattern and cercus shape as in E. subobtusus, epiproct shorter than cercus with short, weakly differentiated branches, and the sinus between the branches shallow and broadly U-shaped.

Natural history. E. wagneri is known only from the male holotype. The specimen was a mature male that was perched at 11:00 hr, apparently on a territory, on a dead stick projecting from a shallow, partly shaded pool in a spring stream at the interface of forest and pasture. No larvae of E. wagneri were found during numerous visits to the area spanning seven years.