Effects of Fruit Cooling on Spotted Wing Drosophila
In some of the first literature written in Japan in 1939 (Kanzawa, T.) about spotted wing drosophila, Drosophila suzukii, (SWD), experiments were made regarding the sensitivity of the egg and larval stages of spotted wing drosophila to periods of temperatures above and below freezing (32o F).
As is noted in the two graphs below, at constant temperatures of up to 35o F, 96 hours or more of cooling resulted in total mortality of spotted wing drosophila eggs and larvae. This was also anecdotally confirmed in tests conducted in 2009 in California.
While temperatures below freezing are not useful to fruit shippers, temperatures in the area of 35o F are useful. However, it is important to note that for success the constancy of the temperature is critical. So, while in an ideal situation constant temperatures of 35o F or a little below are effective in SWD egg and larvae suppression when extended for periods longer than 96 hours, the reality can vary significantly from the ideal. Shipped fruit ordinarily do not experience lengthy regimes of constant temperature as they are moved from place to place. Temperatures of a refrigerator truck can vary by location inside and placement of the produce (ie on the side, towards the bottom etc.), and certainly the temperatures at the point of sale can vary from the ideal to room temperature to even warmer.
Additionally, while initial damage from SWD on raspberries, blackberries and strawberries can be difficult to detect, this is not the case for other fruits such as cherries or blueberries, where the activity of SWD will leave an unsightly blemish.
The take home message from this information is that while extended cooling can be suppressive of SWD, growers should not rely on cooling alone. It will still be important to manage SWD in field.
Thanks to Shinji Kawai for making the information from the 1939 Kanzawa paper available.
This article was posted on the UC Santa Cruz county blog by Mark Bold on March 23, 2010. You can view more blog posts by going to: http://cesantacruz.ucdavis.edu/Strawberry_Nursery_Plant_Production/
Apples
Apricots
Asparagus
Beets
Blueberries
Broccoli
Brussels Sprouts
Cabbage
Carrots
Cauliflower
Cherries
Cucumbers
Dry Beans
Eggplant
Ethnic Vegetables
Garlic
Grapes
Horseradish
Kohlrabi
Leeks
Lettuce / Leafy Greens
Melons
Nectarines
Onions
Parsnips
Peaches
Pears
Peas
Peppers
Plums
Potatoes
Pumpkins / Gourds
Radishes
Raspberries / Blackberries
Rhubarb
Rutabaga
Snap Beans
Squash - Summer
Squash- Winter
Strawberries
Sweet Corn
Sweet Potatoes
Tomatoes
Turnips
Upcoming Events
ASL 105 Employee Development and Training
November 17, 2025 : ASL 105: Employment Development and Training
ASL105: Employee Development and Training
Three leadership practices are essential for supervisors: setting clear expectations, employee training and development, and providing performance feedback.
In Employee Development and Training you will learn best practices to plan and conduct training that engages employees, supports retention, and helps ensure great quality work. You will also learn how to create a culture of continuous learning and performance improvement through employee development, coaching, and career planning. This is a 6-week online course, taught in English.
Topics include:
- Planning effective training programs
- Onboarding new employees
- On the job training
- Staff development
- Creating a culture for continuous learning
- Coaching and career planning
Course begins: Wednesday, November 12 Live Zoom discussions: Tuesdays, 3:00 PM - 4:00 PM ET beginning November 18 through December 23.
Registration closes November 17 at 5 PM ET.
Ag Labor Road Show IX
December 1, 2025 : Save the Date! - Ag Labor Roadshow Webinar 1
In addition to the in-person Ag Labor Roadshow program in our region on December 9, two webinars are scheduled for December 1 and December 22. Each webinar will focus on different program content that is different from the in-person sessions. These webinars are an added benefit to program registration.
December 9, 2025 : Save the Date - Ag Labor Road Show In-Person Event (Greenwich, NY)
Greenwich, NY
The Roadshow delivers essential updates on labor law, regulations, and workforce best practices—tailored for farm owners, managers, and ag service providers. Sessions also focus on practical strategies to boost communication, strengthen retention, and build a positive workplace culture.
The in-person session for Eastern NY is December 9 - Elks Lodge, Greenwich, NY - full day in person session
Additional in-person sessions are:
December 10 - Hilton Garden Inn, Watertown, NY, December 17 - Cornell AgriTech, Geneva, NY, December 18 - Genesee Community College, Batavia, NY
December 22, 2025 : Save the Date! - Ag Labor Roadshow Webinar 2
In addition to the in-person Ag Labor Roadshow program in our region on December 9, two webinars are scheduled for December 1 and December 22. Each webinar will focus on different program content that is different from the in-person sessions. These webinars are an added benefit to program registration.
How to Obtain a Pesticide Applicator License
December 17, 2025
Thinking about becoming a certified pesticide applicator in New York, but aren't sure where to start? Join DEC representative Kenneth Klubek for a discussion on who needs to become a certified pesticide applicator, certification types, examination procedures, and recertification. Participants will have ample opportunity to ask questions during the program.