Gynacantha, Rambur, 1842

Haber, William A., 2019, Gynacantha vargasi (Odonata: Anisoptera: Aeshnidae) sp. nov. from Costa Rica, Zootaxa 4612 (1), pp. 58-70 : 58-70

Key to Gynacantha species of Mexico and Central America

The following key, including the 11 species currently recorded from Mexico and Central America ( Paulson 2018), follows Williamson (1923), Förster (2001), and Heckman (2006). Gynacantha helenga and G. jessei are the only species not yet known from Costa Rica ( Paulson 2018).

1. Without antenodal crossveins basal to first thickened crossvein in fore and hind wings; no black at wing bases..... 2.

1’ With antenodal crossveins basal to first thickened crossvein in fore and hind wings; black patch at wing bases... 10.

2. Pt 4 mm or less; if Pt more than 4 mm, then thorax without black spots................................... 3.

2’ Pt longer than 4 mm; medium to large size; thorax dull greenish-brown with 4-5 small black spots.............. 9.

3. Legs pale colored; middle and hind femora with no distinct black at tips................................... 4.

3’ Legs with some black, at least tips of middle and hind femora black...................................... 7.

4. Small, HW less than 45 mm, body length less than 60 mm; auricles small; one row of cells between anal loop and posterior margin................................................................................... 5.

4’ Medium to large, HW more than 45 mm; auricles large, in lateral view extending far past the transverse carina; two rows of cells between anal loop and posterior margin................................................ auricularis

5. Dark brown stripe covering first lateral suture; thorax with two bright green lateral stripes; male S3 constricted; female S3 weakly constricted; in female S2 space between lateral and ventral carinas narrowed posteriorly; viewed laterally apical 1/4 of cercus with a dorsal lobe......................................................... caudata

5’ No dark brown stripe on first lateral suture; thorax without bright green lateral stripes; male and female S3 not constricted; in female S2 with lateral and ventral carinas subparallel; viewed laterally cercus without a dorsal lobe at apex......................................................................................... laticeps

6. Appendages yellow; venter of S1 with a tubercle near apex; dorsum of middle and hind tibiae pale yellow-brown with black apex..................................................................................... 7.

6’ Appendages black, venter of S1 without a tubercle.................................................... 8.

7. Pt dark – brown or red-brown; femora nearly all black.............................................. tibiata

7’ Pt light yellowish brown; middle and hind femora light brown or orange-brown with apical third or less black................................................................................................ helenga

8. Pt light yellow-brown; middle and hind femora mostly brown or orange-brown with black in apical third or less; middle and hind tibiae yellow to tan on dorsal side; apical third of cercus with a dorsal lobe..................... vargasi

8’ Pt brown or red-brown; legs black except for yellow at base of middle tibia.............................. jessei

9. An opaque black stripe on metepimeron above latero-ventral carina; male with abdomen greatly constricted in dorsal view................................................................................... mexicana

9’ No black stripe on metepimeron above the latero-ventral carina (if a stripe present, then brown and blurry); male with abdomen weakly or not constricted in dorsal view................................................. nervosa

10. Black at wing bases covering median space; top of frons black or obscure without a distinct T-mark; auricle with 3-4 denticles; female abdomen constricted.................................................... membranalis

10’ Black at wing bases limited to less than half of median space; a distinct black T-mark on top of frons; auricle with 7-8 denticles; male S3 constricted................................................................ gracilis