Betrichia longistyla Flint 1983

Betrichia longistyla

This species appears to be most closely related to B. argentinica Flint, with which it possesses in common three ocelli, simple head, antennae, and forewings, single apicomesal process from the seventh sternum, and general form of the genitalia. It is easily recognized by its long, seta-tipped, posterolateral process from the eighth sternum.

ADULT.—Length of forewing, 3 mm. Color of antennae and legs stramineous, head and thorax with pale green and fuscous hair; forewing mostly pale green with an oblique, fuscous band beyond midlength and with apex fuscous with scattered green spots. Forewing with a band of erect hair on basal third of R.

Male Genitalia: Eighth sternum short, bearing a long, slender, upcurved process tipped by a long, dark seta. Ninth segment produced anteroventrally; posterolaterally with a small lobe bearing many setae. Tenth tergite narrowly trianguloid. Subgenital plate long, tapering to a narrow apex, which is hooked ventrad. Claspers fused mesally, long and narrow. Aedeagus with usual basal tube, loop, and midlength complex; apex with a pair of basolateral plates, a pair of basal spines, and troughlike apical sclerite.

MATERIAL.—Holotype (male): BRAZIL, EDO. SANTA CATARINA, Nova Teutonia, 12 Oct 1964, F. Plaumann, USNM Type 100505.

Paratypes: Same data as holotype, but Jan 1963, 4 same, but Jan 1964, 9 same, but Feb 1964, 18 same, but Aug 1963, 10 same, but Oct 1963, 1 same, but Nov 1963, 10.

This is the second species to be placed in this recently described genus, which is known only from the Chilean Subregion. It was not placed in a subfamily by Marshall (1979) but was left incertae sedis. Wells (1980) suggested a relationship with the Australian Maydenoptila, with which I concur.

The immature stages are unknown. Adults are taken near larger streams and rivers.