1999 Entomology Project Report - WSDA PUB 034 (N/1/00)
Laboratory Services Division, Pest Program
Washington State Department of Agriculture

1999 Western Washington Exotic Defoliator Parasitoid Survey

Eric H. LaGasa 1 , Todd A. Murray 2 , Mark Hitchcox 3 , and Amberlynn Pauley-Cawley 3


Background

Project Objectives

Project Methods and Results

Parisitoid Species Identified and Host Records

Pertinent Literature

 

Background

In recent years, insect surveys conducted by the Washington State Department of Agriculture (WSDA) and funded by the USDA Animal and Plant Health Inspection Service (APHIS) Cooperative Agricultural Pest Survey (CAPS) program have detected a number of exotic species of defoliating moth pests (Lepidoptera) in Western Washington State. Several of the exotic species finds represent first record of the pest in the United States, having migrated into Washington from adjacent areas of British Columbia, Canada, where they were likely first introduced into North America. In one case, the exotic pest detection was the first record for the species in North America.

Most of the new exotic pests were likely introduced into the region within the last 20 to 40 years and are now unfortunately well established here. Some may eventually impact diverse northwest economic and environmental interests, including commercial nurseries, row crops, fruit tree production, private and commercial landscape management, and industries which rely on healthy native plant communities such as timber and tourism. For almost all of the exotic newcomers, their modes of entry into North America are unknown.

Exotic plant pests found in Washington State since 1985, year found, and detection status include:

apple ermine moth (Yponomeuta malinellus Zeller) - 1985, New to United States
apple tortrix (Archips fuscocupreanus Walsingham) - 1995, New to North America
apple skeletonizer (Swammerdamia pellicaria (Retz.) - 1994, New to United States
barred fruit tree tortrix (Pandemis cerasana (Hubner)) - 1994, New to United States
cherry bark tortrix (Enarmonia formosana Scopoli) - 1991, New to United States
cherry ermine moth (Yponomeuta padellus L.) - 1993, New to United States
dark fruit tree tortrix (Pandemis heparana (D & Schif)) - 1994, New to United States
European emerald (Hemithea aestivaria (Hubner)) - 1995, New to United States
'golden' leaf roller (Croesia holmiana (L.)) - 1994, New to United States
green budworm (Hedya nubiferana (Haworth)) - 1994, New to Western U.S.
green pug moth (Chloroclystis rectangulata (L.)) - 1994, New to Western U.S.
lesser budmoth (Recurvaria nanella (Hübner)) - 1994, New to Western U.S.
oak skeletonizer (Carcina quercana (Fabricius)) - 1997, New to United States
rose shoot borer (Notocelia rosacolana Doubleday) - 1996, New to United States
straw-colored tortrix (Clepsis spectrana (Treitschke)) - 1998, New to United States

Many of these new species were reared to adult from field collected larvae during several CAPS surveys and any parasitoids present were kept for future analysis. This survey is largely an analysis of that compiled parasitoid material. Parasitoid predation is a key factor in determining whether introduced exotic species become significant economic pests here.

1999 Project Objectives

  1. Identify parasitoids reared from identified exotic defoliator larvae.
  2. Summarize parasitoid/host associations and determine parasitoid prevalence (e.g. percent parasitism observed).

Inquiries regarding availability of this publication in alternative formats shold be directed to the WSDA Receptionist at (360) 902-1976 or Telecommunications Device for the Deaf (360) 902-1996.

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