Landscape Message: May 6, 2016

• Winter Moth: (Continued monitoring) Operophtera brumata egg hatch has been complete for the past few weeks and 1st and 2nd
  instar caterpillars are being found in host plants such as maple,
  apple, and blueberry. A few 3rd instar caterpillars may also be present
  (see Southeast Region update). Hosts whose buds opened earlier this
  season may be more significantly impacted, however as we are seeing oak
  buds open the caterpillars are quickly taking advantage of the newly
  available real estate. The Elkinton Lab has observed oak buds in
  Falmouth and Yarmouth to be further along in development than those on
  the south shore in some cases (the Cape is usually a week behind but
  perhaps this is not the case in all areas on the Cape this season). Silk
  and frass (excrement) may be seen on newly emerged leaves of hosts and
  tiny caterpillars seen with a hand lens. Continue to monitor susceptible
  hosts for the presence of caterpillars. For green industry
  professionals looking to manage winter moth in the landscape, wait until
  leaves have opened to treat with insecticides. By waiting until the
  leaf expands, it is easier for the insecticide to reach the caterpillar
  than when it is protected inside the bud. Products containing active
  ingredients such as spinosad and pyrethroids are available. Apples,
  crabapples, and other flowering plants should not be sprayed with these
  products while in bloom to avoid unintended impacts to pollinators.