In the southwest canyons from western Texas to southern California and northward into Nevada, Utah and Colorado, a closely related group of emerald-green moths occur in a surprising diversity greater than that found anywhere else in the US and Canada. The number of distinct species is at least in part the result of evolutionary patterns overlaid on a mountain and desert geography that creates unique and isolated habitats where higher elevation communities of vegetation on mountain slopes are separated from other locations by large expanses of dry, arid desert. Over the last seven years, Friends’ Central research teams have explored specific locations in New Mexico, Arizona, and Texas, collecting adults and whenever possible eggs of eight different moths in the genus Nemoria as well as related species in the genus Chlorosea and the genus Dichorda. This work complements ten years of work with eastern species in the same group studied from Vermont to South Carolina, photographing and rearing eight more distinct species of Nemoria and Dichorda.
Nemoria obliqua (left) and Nemoria intensaria (right)
Among the southwestern Nemoria, several species are quite uncommon or even rare and at least one pair of species is still poorly resolved and awaiting fuller illumination of the the distinction between two groups. Nemoria caerulescens and Nemoria intensaria are remarkably similar in their outward appearance, being separated from each other by just a handful of very subtle and rather variable outward characteristics. The elaborate anatomy of internal genitalic architecture so often used to distinguish species does not offer much help in separating these species since the genitalic structures are said to be indistinguishable from each other. Many collections, including those in the Smithsonian and the American Museum of Natural History are still unclear in their placement of individual moth specimens between these two species. Given that the two species overlap over much of their natural range, some might even question whether the two names constitute two distinct species or are in fact representing diversity and seasonal or geographic variation in form within one species.
In 2007 and again in 2009, we collected female moths of Nemoria caerulescens in northern New Mexico and successfully reared larvae from eggs to adult in our lab at Friends’ Central. This work represents the first documentation and imaging of the larval form for this species, and offers a critical piece of evidence in the examination of the taxonomic position of Nemoria caerulescens and Nemoria intensaria. Michael Canfield at the MCZ at Harvard has sequenced Nemoria caerulescens DNA and submitted the sequence data to the national GenBank database. To complete our study of this pair of Nemoria species and a third related member of the group, Nemoria festaria, we propose a field expedition to the region best known for clear examples of Nemoria intensaria as well as the type specimen for this species, collected from central Utah. Utah offers examples of distinct N. intensaria that bear important abdominal markings that are not found on Nemoria caeruelscens. We have chosen study sites for 2013 corresponding to the elevatiosn and habitats where Nemoria intensaria has been previously collected in Utah and Nevada, and hope to obtain adults with fresh tissue samples for DNA sequencing as well as eggs to rear and photograph larval forms of Utah intensaria.
Additionally, we will keep a close eye out for a relatively rare pink-shaded emerald moth named Nemoria latirosaria (see below). Known from northern Arizona and Utah canyons, this moth probably flies only briefly in late June and early July.
