|- click to enlarge -|
In late October, 2009, the managers of the Back River Wastewater Treatment Plant in Baltimore, MD sought assistance in mitigating what they described as an “extreme spider situation” in their sand filtration facility. The building, consisting of almost four acres (16,099 square meters) under a single roof but with no side walls, had been prone to extensive colonization by orb-weaving spiders since its construction in 1993. However, the present infestation was considered to be worse than normal, and the facility’s maintenance and operations personnel had voiced concerns over the potential risk of bites.
As an interagency team with expertise in arachnology, urban entomology, and structural pest management, we were unprepared for the sheer scale of the spider population and the extraordinary masses of both three-dimensional and sheet-like webbing that blanketed much of the facility’s cavernous interior. Far greater in the visual impact of the spectacle was nothing less than astonishing. In places where the plant workers had swept aside the webbing to access equipment, the silk lay piled on the floor in rope-like clumps as thick as a fire hose.
Spider webs hanging from trolley beams.