Lachesilla horni n. sp. Male

(Figs 40–42)

Diagnosis. Hypandrium wide, with a setal field on each side. Posterior processes proximally wide, distal halves short, slender, curved inward. A transverse sclerotized band along posterior border, between the posterior processes. Phallosome V-shaped anteriorly, apodemes slender, widening distally; distal third dilated, with a mesal bulge on outer border, posterior border straight, with a pointed apophysis directed outward.

Description. Color (49 years in 80% ethanol). Body chestnut brown. Compound eyes brown, ocelli hyaline, without pigmented centripetal crescents. Maxillary palps brown. Tergal lobes of meso- and metathorax slightly more pigmented than surroundings. Wings hyaline, veins brown, R1 bordering pterostigma ochre. Abdomen whitish, with brown subcuticular rings faded ventrally.

Morphology. As in diagnosis, plus the following: Compound eyes below the level of the slightly emarginate vertex. Forewing pterostigma long, wider distally, Rs-M meeting at a point, areola postica high, triangular, rounded apically (Fig. 40). Hypandrium and phallosome (Fig. 42). Paraprocts (Fig. 41), broad, rounded, setae as illustrated, sensory fields with 13 trichobothria, a pigmented band limiting sensory fields on anterior border. Prong mid sized, distally truncate. Epiproct (Fig. 41), straight anteriorly, distinctly bilobed posteriorly, setae as illustrated.

Measurements. FW: 3045, HW: 2267, F: 590, T: 1076, t1: 377, t2: 125, ctt1: 20, Mx4: 203, f1: 334, f2: 316, f3: 257, f4: 191, f5: 119, f6: 115, f7: 88, IO: 419, D: 176, d: 109, IO/d: 3.84, PO: 0.61.

Specimen studied. Holotype male. GUATEMALA. 48 km N Huehuetenango. 3.ix.1968. Beating dead leaves of herbaceous plants on upper edge of cloud forest. E. L. Mockford (ISU) .

Etymology. This species is dedicated, in memoriam, to G. Horn, co-author of the Insecta. Coleoptera . Serricornia. Volume III, Part 1 (1882–1897), of the Biologia Centrali-Americana.

Remarks. This species is close to L. jacobyi n. sp., decribed below, from which it differs by having the posterior processes of the hypandrium much shorter and slender, in having a transverse, sclerotized band in the hypandrium, between the posterior processes, and in having the distal ends of the phallosome apodemes only with the outer postero-lateral corners acuminate, directed outward.