Spring is fading into summer here in Maryland, and the Lamp lab has confirmed that our resident gnat, Simulium jenningsi, is back for the start of the season in Washington County. Reports of black fly swarms reached our lab earlier this month. After identifying specimens from these early swarms collected by a volunteer, we found that the flies were indeed S. jenningsi. S. jenningsi has several generations per year, and as we learned from our 2014 sampling S. jenningsi can be found in Maryland well into November.
Further north into New England, the major nuisance black flies are in the genus Prosimulium. These flies bite a lot harder than S. jenningsi, but have one generation per year and are only around for a few weeks in the spring. Last year we collected Prosimulium adults in April in Washington County. While these flies were also caught flying around our heads, their numbers were not nearly as large as what we have seen with S. jenningsi.
With the return of S. jenningsi, the Lamp lab is getting ready for a new year of sampling. This year we will revisiting old larval and adult sampling locations, expanding our study into Montgomery and Prince Georges Counties, and testing out novel methods of surveying larval populations. Stay tuned for updates!