New York Natural Heritage Program
Gray Petaltail
Tachopteryx thoreyi (Hagen in Selys, 1858)

Threats [-]
Since seepage areas are the key larval habitat for this species, any activities that alter the quality or quantity of groundwater seepage in an occupied area would pose a threat to gray petaltails. The most important likely negative impacts would come from changes in natural hydrology through the building of dams, increases in sediment load of the seepage (such as might occur should extensive logging take place in or adjacent to the seepage), changes in dissolved oxygen content, direct effects of pesticides, and chemical contamination by runoff or agricultural discharge. Direct, intentional killing by people is a possible threat to this species. In at least one state park, petaltails squashed by park visitors have been observed. Petaltails are not wary and occasionally land on people whose first reaction is probably to swat the insect.

Conservation Strategies and Management Practices [-]
Consideration should be given to providing information to the public at state parks where this species occurs. The tame and harmless nature of the insects could be stressed in order to reduce the likelihood of the dragonflies being killed by startled hikers. For example, a photograph and brief information sheets could be provided at kiosks located near the entrances to trails during the late May-July flight period.

Research Needs [-]
Although the larvae are known to be associated with seepage areas, and seepage areas are very apparent at some known sites, probable larval habitat is less apparent at some others. Efforts to locate larvae or exuviae to determine specific larval habitat is warranted for at least some of the known sites. A mark-recapture study similar to the study conducted by Dunkle (1981) in Florida would provide the basis for a better overall population estimate and long-term monitoring efforts for the species.