Environmental monitoring potential of the Odonata, with a list of rare and endangered Anisoptera of Virginia, United States

Odon. are useful environmental monitoring agents. Most spp. show specific responses to environmental disturbances. The nymphal stage is the most reliable for obtaining population information, but the nymphs of many spp. remain undescribed. Adult Odon. can be easily identified, but high adult vagility necessitates careful evaluation of recorded occurrences. High vagility does, however, insure rapid re-establishment in suitable habitats. An unusually high number of Virginia Anisoptera may be considered rare or possibly endangered, many of which are found only in undisturbed habitats, suggesting that they are very sensitive to environmental disturbances. A list of 60 rare and endangered spp. is given in a table along with notes on their status in Virginia. The environmental monitoring potential of the Odon. cannot be fully achieved unless more attention is given to nymphal descriptions, and baseline faunal surveys.