New York Natural Heritage Program
Extra-striped Snaketail
Ophiogomphus anomalus Harvey, 1898
Insects

Threats [-]
Snaketail larvae require high water quality with high dissolved oxygen content and substrates that have little sedimentation (Lee 2007). Due to the fact that these are intolerant organisms, Ophiogomphids are important components of macroinvertebrate indices to rate water quality in New York. Thus, any activity which might lead to water contamination or the alteration of natural hydrology could impact Extra-striped Snaketail populations (Holst 2005). Such threats might include agricultural run-off and other pollutants, dams, shoreline modifications, increases in the sediment load of rivers, and changes in the dissolved oxygen content (Holst 2005, Lee 2007). Maintaining a forested buffer around the river would be beneficial to adult snaketail populations (Lee 2007). On the Upper Delaware River, the hydrological flow has been altered by two large water supply reservoirs on each of the two branches upstream from Hancock and hydroelectric plants have been built on two major tributaries. The reservoirs act as sediment traps resulting in coarsening of the river bed downstream leading to a lack of finer sediments probably required by nymphs. High flow releases in late summer which are contrary to the natural flow regime may also have a detrimental effect on the larvae (Soltesz 1994).

Despite finding extremely high larval densities (20/square meter) in June at the Artoostook River in Maine, Gibbs et al. (2004) never observed any winged adults of this species during July and August, suggesting either 1) highly cryptic terrestrial behavior, 2) extremely high mortality rates, or 3) habitat segregation.

Conservation Strategies and Management Practices [-]
Further searching and larval sampling may be necessary before specific stewardship needs at a location can be identified. However, any measures to reduce water contamination or hydrological alteration such as agricultural run-off, shoreline development, and damming that would affect river flow should be considered when managing for this species (Holst 2005).

Research Needs [-]
Further research is needed to define the distribution, life history, and population size of the Extra-striped Snaketail. In addition, research is required to understand the habitat requirements and threats to this species, and to create appropriate management guidelines for its persistence in known locations (Holst 2005, Lee 2007).