New York Natural Heritage Program
Spatterdock Darner
Rhionaeschna mutata (Hagen, 1861)

Threats [-]
Little published information is available citing specific cases of negative impacts to this species or other lake-dwelling odonates, but any activities that degrade the sensitive hydrology of these habitats would threaten populations of these species. Examples include eutrophication and changes in dissolved oxygen content, direct effects of pesticides (e.g. for mosquito control or from agricultural runoff), increases in the sediment load of the lake (such as might result from agricultural runoff or removal of vegetation from the adjacent uplands), chemical contamination by runoff of agricultural or other discharge, and acidification of lakes by airborne industrial emissions. Groundwater withdrawal is also a likely threat at suitable sites on Long Island. Removal of large areas of forest or shrub habitats adjacent to occupied lakes and ponds could also threaten populations, as these adjacent habitats are important for recently emerged adults until they reach maturity.

Research Needs [-]
Research aimed at obtaining information on population size at occupied sites would be useful in determining the overall population for this species in the state. Research on larval habitat requirements may provide a better understanding of why the species is uncommon.