The oldest specimens I know of at University of Colorado date back to 1877. Ironically, we have no specimens of the Rocky Mountain Locust, Melanoplus spretus, that plagued the front range of Colorado in the 1870s before being wiped out.
Entomology Collections Manager
University of Colorado Museum of Natural History
265 UCB MCOL
Boulder, CO 80309-0265
For me, the single thing that has emerged in this discussion is the very short time that we have been sampling/collecting insects in North America. What we are hearing is that most collections have specimens from no more than 150 years ago. Does anyone else find this a soberingly very short (and inadequate) time for us to truly know our fauna? I worry that the pace of basic taxonomic progress is being rapidly outpaced (and left behind) by technological advances in methodology, analytical tools, and information technology resulting in less of a focus on the basic questions of what the species are, how do we recognize them, where do they live and what do they do.