Aquatic Insects of the West River and Salt Marshes ... - Yale University

166 INTERDISCIPLINARY RESTORATIONAquatic sites lower on the river within West River MemorialPark yielded only chironomid larvae (Diptera: Chironomidae) anda few water scavenger beetles (Coleoptera: Hydrophilidae). Otherresearchers involved in the West River biological survey also foundonly chironomid larvae in the lower West River (C. Cuomo, GeologyDepartment; J. Moore, Biology Department, Yale University,personal communications). The restriction of freshwater organismsto upper parts of the river was consistent with concurrent watersalinity data recorded by Cuomo and Zinn (this volume). Rainfalldata indicate an area-wide drought that began in 1993. The resultinglower water levels, coupled with the effects of an open tide gateduring 1995, undoubtedly contributed to elevated salinity levels.This effectively shifted the communities of freshwater insects fartherupstream, beyond the reach of tidal influence. Possibly, the currentaquatic community predicts the future insect community that willbe found when salinity levels rise to those sustaining a salt marsh.The shoreline communities on the mud and clay banks along theriver and reflecting pool were host to a diverse group of beetles andother insects. Thirty-two species from nine beetle families were discoveredat the waters’ edge. Of these, the species of the coleopterangenus Bembidion are well-known inhabitants of salt marshes(Olmstead and Fell 1974). On the eastern side of the central island, alarge colony of tiger beetle larvae Cicindela duodecimguttata Dejean(Cicindelidae) were discovered inhabiting clay banks adjacent to thereflecting pool. No tiger beetles were seen on the other sand bars inthe river during the collecting period.Taxa found at West River Memorial Park had little in commonwith the salt marsh communities. Nonetheless, several salt-associatedinsects were found in the park. Two carabid beetle species,Bembidion contractum Say and B. versicolor LeConte, and one cleridbeetle (Enoclerus rosmarus Say), collected in the park were alsofound in one or more salt marshes. Among the Diptera collected atthe West River, one Notiphila species (Ephydridae) was found alsoat the Hoadley and Pine Creek salt marshes. No new species or thoseconsidered by federal or state agencies to be endangered, threatened,or of special concern were encountered at the West River.Bembidion sp. (redrawn fromGreene 1968)NEW RECORDSDuring our collecting, a new state record was established for theseed bug Chilacis typhae (Perris) (Heteroptera: Lygaeidae). Thisexotic from Europe is restricted to the heads of cattails (Typha spp.).The first record of this species in North America was from Pennsylvaniain 1986 (Wheeler & Fetter 1987). In the West River, it wasBULLETIN 100