Distribution of an Invasive Ant, Myrmica rubra (Hymenoptera: Formicidae), in Maine

Groden, Eleanor; Drummond, Francis; Garnas, Jeffry; Franceour, Andre; Department of Biological Sciences, University of Maine

A description of an invasive ant. Abstract: 'Introduced populations of the north temperate ant species, Myrmica rubra (l.), have become pestiferous in various locations in the northeastern United States, particularly in coastal communities in Maine. Native populations of this ant are widely distributed throughout northern Europe and western Asia; however, nest densities in its native range do not usually reach the high levels observed for many introduced populations. This aggressive ant readily stings, and because of its high densities, homeowners continually encounter nests at a frequency that interferes with use of their properties. Surveys were conducted in Maine from 2001 through 2004 to determine the statewide extent of the current infestation. Nests in established populations in coastal Maine were sampled from April through September to assess seasonal changes in the density and composition of colonies. Similarities and differences between introduced populations of M. rubra in Maine and published reports of this species in Europe are discussed. Museum records of this species in North America were also researched and are presented. Methods: In 2003 sampling efforts were focused on determining the extent of the infestation in Acadia National Park and surrounding communities on Mt. Desert Island. Requests for information on infestations were published in the newspaper in the spring and reports received were followed up with a visit to the site for sampling. Results: Intensive sampling on Mt. Desert Island has shown that there are multiple patches of infestation, including a large infested area that extends along Rte 3 from 2 km north of the Bar Harbor town center to 1.5 km south, including most of the town (Fig. 2). It is uncertain whether this infestation is contiguous with the infested areas along the northern coast of the island from Hadley Point to Salisbury Cove, and infested areas south to Sand Beach within Acadia National Park, or whether these areas represent discrete populations with limited gene flow. Of not is the fact that at several locations, infested patches seem to be limited by human or natural barriers, such as roads or streams or mature spruce-fir forest. ' The article goes on to compare populations in Maine and other places to their native ranges, noting that Maine populations have unusually high densities comparatively and are becoming a serious problem for residents in coastal Maine communities. /STUDY LOCATIONS:/ /MOUNT DESERT ISLAND/

Distribution of an Invasive Ant, Myrmica rubra (Hymenoptera: Formicidae), in Maine

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