Epigomphus morrisoni, Haber, 2017

Haber, William A., 2017, Three new species of Epigomphus (Odonata: Gomphidae) from Costa Rica, Zootaxa 4282 (1), pp. 73-94 : 87-88

Epigomphus morrisoni new species

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

Specimens examined. Holotype male: COSTA RICA, Provincia Puntarenas, Monteverde, Río Guacimal (10.28, - 84.82), 725 m, 22 June 2010, leg. WAH ( INBIO, INB 0004319187 ).

Etymology. This species is named for my friend and colleague Fredric Morrison, a great naturalist, devotee of the Gomphidae , and trusted companion who has accompanied me on many Odonata expeditions in Costa Rica and Ecuador.

Description. Male holotype. Head. Maximum width 7.2 mm; shiny dark brown above ( Fig. 1 c, 9b); labrum dark brown with a blue-gray spot near lateral margin; base of mandible and gena pale; top of frons with a pale stripe covering about 2/3 of surface, narrowed in middle and divided by a dark line; antennae dark brown; eyes blue in life; lateral ocelli equidistant from eye margin and mid line; postocellar surface nearly flat, barely impressed; posterior margin of occiput with a rounded ridge, a pair of lateral conical tubercles on dorsum that are collapsed in holotype, rear margin with central third indented, a pair of low rounded tubercles on posterior side of ridge close to eye margins; underside of head dark brown on upper half shading to cream on lower half.

Thorax. dark brown with pattern of stripes similar to E. subobtusus ( Fig. 1 c; 9b). Prothorax fore lobe with anterior margin pale; mid lobe with a pair of contiguous pale spots in center and a pair of larger pale spots on lateral ends. Pterothorax: mesepisternum with two pale antehumeral stripes, upper stripe separate from pale collar stripe and not reaching posterior margin, lower stripe narrowed in middle; mesepimeron with a complete central stripe, narrowed posteriorly, then widened at end; metepisternal pale stripe broad at base, narrowed to a point and almost separated into a posterior spot; metepimeron pale except for a narrow brown upper border and a dark central bar on anterior half; mesinfraepisternum with a pale triangular patch at lower posterior corner; metinfraepisternum mostly pale, shading to brown in upper third; metasternum pale, unmarked. Legs: fore and mid legs with femur dark brown on anterior side, shading to light brown on posterior side; no pale stripe on inner surface of fore femur; hind femur pale brown, dark only at tip. Wings hyaline with dark brown venation ( Fig 3 b); basal subcostal crossvein present; cubito-anal crossveins 3 in FW, 2 in HW; FW Ax 19, 17 with 7 thickened; Px 13, 14; HW Ax 14, 13 with 7, 6 thickened; Px 13, 12; pterostigma dark brown, opaque, 3.6 mm in FW, 4.2 mm in HW; crossveins above supratriangle between arculus and point of branching of RP 5, 6 in FW, 3, 4 in HW; post-triangular cell space in FW with two rows of cells for 10, 9 cells.

Abdomen dark brown with pale markings cream-yellow; dorsum of S1–4 with a pale dorsal line (widened on S1–2); sides of S3 pale on basal 3/4; sides of S4–6 with pale basal triangles; S7 pale in basal 3/4; side of S8 with a tiny pale spot on lower basal corner; S9 unmarked; S10 with a low hump barely divided by a central longitudinal groove.

Abdominal appendages. Cercus as in E. subobtusus ; 2.5 mm long along dorsal line, apex with line of 7–8 small teeth; epiproct 1.6 mm along dorsal line, slightly shorter than cercus, similar in shape to E. subobtusus , except apex squared off and bearing a strong dorsally directed tooth, which is slightly recurved at tip and bent slightly inward; sinus between branches 95o; on dorsal side, margin of sinus with a rounded bump extending about 3/4 of sinus length ( Fig 4 c; 10b).

Secondary genitalia. Vesica spermalis similar in shape to that of E. subobtusus ( Fig. 5 c, d).

Measurements (mm). Total length 50; abdomen 38; FW 35; HW 33, maximum width 8.2.

Female. Unknown.

Diagnosis. Thoracic pattern and cercus shape as in E. subobtusus , branches of epiproct forming a 95o inside angle compared with 64–78o in E. subobtusus (mean 72.4 o, s.d. 4.97, n=10), apex of epiproct with a strongly developed dorsal hook that is inclined slightly inward (slightly outward in E. subobtusus ).

Natural history. To date E. morrisoni is known only from one male from the type locality. No additional individuals were found in many subsequent visits to the area. The type specimen was a mature male that was perched (apparently defending a territory) on an upright dead stick projecting from a shallow, partly shaded pool in a spring outflow at the interface of a forest and pasture about 11:00 hr. Larvae and adults of E. subobtusus and E. tumefactus were collected at the same pool, but no larvae that might have been E. morrisoni were found there or in nearby streams.

Figures

FIGURE 1. Epigomphus bosquenuboso: lateral scans of a) male; b) female. E. morrisoni: c) lateral scan of male. E. wagneri: d) lateral scan of male.

FIGURE 3. Wings of male Epigomphus, dorsal view: a) E. bosquenuboso, b) E. morrisoni, c) E. wagneri.

FIGURE 4. Abdominal appendages of Epigomphus species: a) E. bosquenuboso lateral view, ventral view; b) E. morrisoni, lateral view, ventral view; c) E. wagneri lateral view, ventral view.

FIGURE 5. Distal segment of vesica spermalis of Epigomphus species with lateral view on left, dorsal view on right. E. bosquenuboso: a, b; E. morrisoni: c, d; E. wagneri: e, f. E. bosquenuboso female: g) dorsal view of head; h) vulvar lamina.