Hundreds of different birds and mammals, for example, depend upon invertebrate populations as food sources, and many of the higher plants rely on invertebrate pollinators and seed dispersers. Although society obviously appreciates some invertebrates, such as the honey bee and its role in the pollination of agricultural crops, the understanding and, in turn, conservation of most invertebrates has lagged far behind. On the other hand, with the exception that aquatic organisms are managed by the Fish and Boat Commission, most invertebrates do not fall under the trusteeship of any such caretaker. Fortunately, the U.S. Endangered Species Act applies to all living species, so at least some attention is focused upon invertebrates thought to be threatened or endangered on a national level. The decline of the once widespread and regularly found regal fritillary is both mysterious and alarming.
Invertebrates are excellent environmental quality barometers.
Nonetheless, virtually no attention has been paid to the plight of the fritillary or virtually any other non-aquatic invertebrate. Of the 100 or so species of butterflies and skippers in our state, many are just as worthy of attention as the regal fritillary. Several of the remaining 27 have also declined. Seven mussels have been listed as Endangered under the U.S. Endangered Species Act. Nine Pennsylvania mussels have been enlisted as endangered under the U.S Endangered Species Act, but seven of these are already extirpated in our state.