Larval feeding type: Probably a catkin feeder
Larval substrate: Unknown, but probably similar to dianella, i.e. Pinus spp.
Phenology: Adult: 7/11 to 8/26 (2 records)
Comment: Can easily be confused with Calosima dianella, which is usually larger (11-14mm, compared to 9-12mm) and more uniform ochreous-yellow rather than yellowish-white. The original descriptions of these two species states that the forewing color is very similar, except that dianella is a more pronounced yellow and the 'extreme costa' is whitish in dianella, but brown in argyrosplendella (Dietz had just a single specimen of dianella and three argyrosplendella, so the differences may not be reliable). The brown in our specimens of argyrosplendella is very weak and difficult to see (and may be due to wear). The costa is however not paler as can be seen in most dianella. The other differences given in the original description can be found in the fore- and hindwing shapes, but these are small and not really useful. This species can get worn very quickly and is then more silvery-white or silvery-gray. The genitalia are very similar to C. dianella, the main difference being found in the uncus.
Status in MA (automated assessment): Restricted distribution, rare
Status in N. America: Native
MA Endangered Species Act status: None
First Year Reported: 2016
Last Year Reported: 2016
Distribution by County: Middlesex, Barnstable
Number of Records: 2