Revision of Neotropical Nectopsyche

Researcher: Ralph Holzenthal

In the general entomological literature, caddisfly adults are often described as drab, somber, secretive, moth-like insects. In fact, most species of caddisflies are brown, gray, or yellowish, often with mottled patterns of these colors. These color patterns are imparted by the distribution of colored hairs and scales on the wings or by the color of the underlying wing membrane itself. However, not all caddisflies are drably colored. Many species in several families have intricate patterns of color on the wings and body, and some are very brightly colored, even rivaling their cousins the Lepidoptera in the brilliance of their coloration. One such genus, Nectopsyche, of the long-horned caddisfly family Leptoceridae, contains species that are among the most brilliantly colored of all Trichoptera.

In spite of their conspicuous coloration, the taxonomy of the species of this New World endemic genus is poorly know and in need of revision. The male genitalia, highly diagnostic for most species of caddisflies, are very similar among the species of Nectopsyche and often variable within populations. Setal lobes, especially on the inferior appendages are often of different lengths or number, sometimes even between the left and right halves of a specimen. Reliance on genitalic differences alone is not sufficient to discriminate among some species. On the other hand, several non-genitalic characters, including wing and body coloration, eye size, and body size, in addition to features of the male genitalia, when carefully examined and taken together seem to offer useful characters to distinguish and diagnose species. However, the hairs and scales become rubbed off on specimens collected and stored in alcohol, rendering alcohol preserved specimens even more difficult to identify. If specimens are collected in dry cyanide kill jars and then carefully manipulated and pinned, the pattern of hairs and scales will remain intact and prove very useful in diagnosing species.