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
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.
2026 Winter Cut Flower Webinar Series
January 6, 2026
The fifth annual CCE Cut Flower Webinar Series begins on January 6, 2026 and continues over 5 weeks on Tuesdays. This is a very popular series of online events you won't want to miss, with topflight speakers, a wide variety of subjects concerning growing cut flowers and plenty of interaction between speakers and attendees.
Tuesdays 1pm-3pm January 6, 2026 - February 3, 2026 (The webinar held on February 3 will run 1pm-4pm)
Cost: $60.00 for all five sessions, $20 for single sessions
Webinars will be recorded, and all the recordings will be sent to registrants for future review.
Expanding Farm Sales: Markets, Profits, and Branding Series
January 10, 2026
Looking to diversify where you sell your farm products? This four-part workshop series helps farmers explore new opportunities in direct-to-consumer, wholesale, and institutional markets. Learn how to meet buyer expectations, price for profitability, and build lasting relationships that support your business goals. Participants will strengthen marketing and communication skills, evaluate which sales channels best fit their farm, and connect with buyers, distributors, and local partners who can help expand their reach. Whether you're just starting out or ready to grow your market presence, this program will help you chart the right path for your farm's future.
Four Session Series: Saturdays from 10AM to Noon, January 10-January 31, 2026
Attend at one of three locations: Schoharie Extension Center - Cobleskill, NY; Otsego Education Center - Cooperstown, NY; Via Zoom
Pre-registration is requested! Fee: $25 Register Here
Any questions can be directed to Kelley Doolin at kmd322@cornell.edu