Alexandria 'Alex' Wenninger University of Alaska Fairbanks - Institute of Agriculture, Natural Resources, and Extension - Integrated Pest Management Program (WPDN)
The Communicator: Volume 6, Issue 6, June 2025
Alaska's short growing season and cold climate make edible crabapples and their hybrids a popular choice for apple growers in Alaska; their fruit is used to make applesauce, cider, jelly, apple butter, and more. In October 2022, an apple grower in Wasilla, Alaska brought samples of misshapen apples containing swollen seeds to diagnosticians at the University of Alaska Fairbanks Integrated Pest Management Program (AK IPM).
Dissection of the seeds revealed small, white larvae inside. AK IPM diagnosticians reared the larvae to adults which allowed chalcid taxonomist Dr. Petr Janšta (Staatliches Museum für Naturkunde Stuttgart) to confirm the identity of the wasps as those of the apple seed chalcid (Torymus druparum).
The apple seed chalcid was first recorded in North America in New York in 1906. Over 100 years later, AK IPM documented the first record of the apple seed chalcid in Alaska and identified strategies for growers to manage this non-native pest. This work also improved our broader understanding of the insect pest issues that impact apple growers in Alaska.
The full story about the apple seed chalcid investigation is available online or in pdf format.
Funding from the National Plant Diagnostic Network helps us respond to emerging insect concerns affecting Alaska's growers.
This work was also partially funded by the Crop Protection and Pest Management Program (grant no. 2021-70006-35561 & 2024-70006-43668) from the USDA National Institute of Food and Agriculture.
