Guapinannus sinuosus, sp. n.

(Figs 3, 7, 9)

Holotype. Male. MEXICO: Chiapas: Palenque, 15.63333°N 92.65°W, 1640m, 02 Jul 1983 – 30 Jul 1983, S. B. Peck, J. Kukalova-Peck, R. S. Anderson, 1♂ (UCR _ ENT 00102050) (FMNH).

Paratypes: MEXICO: Chiapas: El Bosque (6.6 mi SW) , 17.01667°N 92.78333°W, 1463 m, 29 Aug 1973, A. F. Newton, 7♀ (UCR _ ENT 00101241, UCR_ENT 00102051-UCR_ENT 00102053) (FMNH) . Playón de la Gloria, 16.16028°N 90.90139°W, 160 m, 26 Jun 2008, collector unknown, 1♂ (UCR _ ENT 00120069) (MTEC) .

Etymology: Named for the s-shaped vesica after “sinuosus” Latin for bending.

Diagnosis: Recognized by the mid-sized body length (1.49 mm), C+Sc margin broad anteriorly and more slender posteriorly, distinctly double s-shaped margin of rc1, rc, tc cells (black arrow) (Fig. 3), and relatively tick and s-shaped vesica (Fig. 7).

Description: Male: Total body length 1.49 mm; length from posterior margin of pronotum to posterior wing margin 0.9 mm; greatest width across pronotum 0.54 mm. General coloration: uniformly pale. Vestiture: Dorsum with sparse setae, setae short; setae on posterior margin of forewing long. Structure: Head: Eye almost half as high as head; muscle scars large. Thorax: Anterior pronotal margin concave, posterior margin slightly concave; pits on pronotum small, evenly distributed; scutellum in dorsal view gradually narrowed to tip, tip pointed. Forewing: With outline elongate oval; membrane contributing about one third of forewing length, posterior distal margin rounded, vein-tracing areoles on proximal part of wing absent; C+Sc uniformly broad; distal process of R weakly developed; An1 wing organ on corium strongly inflated, without notch articulating with claval process, rounded, without median notch; rc1 about 3 times as long as wide, slightly wider anteriorly; rc about 5 times as long as wide; tc about 3 times as long as wide; distal margin of rc1, rc, and tc cells double s-shaped; rc2–3 almost triangular; cub almost reaching wing margin; dc1 with basal portion relatively wide and short. Legs: Claws long. Genitalia (Fig. 7): Pygophore without lobe on right side; vesica with between half and one loop, not reaching right pygophore margin, thick at midpoint, tapering to acute tip, close to tip slightly s-shaped; anophoric ridge with process, process short, with single lobe curved, tip pointed; right paramere curved, tapering, basal process broad; left paramere straight, tapering, basal process narrow.

Female: As in male and generic description.

Collecting method and habitat: Collected using Berlese extraction, flight intercept trap, and sifting leaf litter in closed forest, cloud forest with pines, mature wet forest, and rainforest.