NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Only two known EO's despite intensive surveys at a variety of vernal pool habitats throughout the Delmarva Peninsula during 1982-1998. Apparently habitat restricted and may have limited dispersal capabilities. Highly vulnerable to habitat disturbances (e.g., logging, development), certain forms of gypsy moth and mosquito control, factors that may affect pool hydrology (e.g., groundwater withdrawal for irrigation), and environmental stochasticity given the small, isolated nature of the two known EO's. There is strong concurrence among taxonomic experts that it is highly unlikely any other localities have been found on the Delmarva Peninsula or elsewhere based on published literature and a review of records from major museum collections.
Other Considerations: Although vernal pools are fairly common on the Delmarva Peninsula, vernal pool habitat conditions at Seth Forest Demonstration Area appear to be unique (e.g., in terms of pool size, depth, forest age, lack of pool vegetation, lack of Dimilin spraying, etc.). Numerous pools have been surveyed since 1982 with no success. Surveys have focused on pools with habitat conditions as similar as possible to those at Seth but a variety of other woodland pool habitats (e.g., Delmarva Bays, "wet" woods, pine-dominated woodland pools) have also been surveyed. The possibility that this species is flightless would further indicate that it is a local endemic and habitat restricted. Taxonomic experts from Smithsonian Institution's National Museum of Natural History (P. Spangler, W. Steiner, C. Staines) and University of Maryland (L. Hellman), including the foremost authorities on the Hydrochus and aquatic beetles in general in the mid-Atlantic region, are not aware of any published records or specimens from major museum collections. Several of these experts have participated in survey efforts throughout the Delmarva Peninsula and surrounding region and were involved in both the species' discovery and rediscovery.
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