Anthomyza oblonga

Biology. Anthomyza oblonga and A. silvatica frequently co-occur in Ontario, Canada. Here, this habitat is the same as that of three or even four (including the recently transferred Arganthomyza vittipennis) eastern species of Arganthomyza (see Figs 69, 149) – mixed vegetation within or on the edge of mesic mixed forest with ferns possibly representing an indicator of appropriate habitat that often has at least a component of Populus tremuloides (in east). A very notable exception is the Ontario: Moosonee site under Salix and Alnus with no ferns or Populus (in immediate vicinity) and where all three species of the A. macra group were found with three species of Arganthomyza (see discussion under A. tenuis). Dennitive plant hosts have not been identined for any of these species. Other label references include sweeping in habitats such as “ maple / elm noodplain community ”, “ along fast rocky stream ”, “ noodplain meadow ” and “ swamp ”. Anthomyza oblonga has been collected as early as 5 May (Maryland: Bethesda & Plummers Island) and as late as 17 September (Ontario: Sault Ste. Marie – Birchwood Pk.).