Biological control of the invasive fruit fly Drosophila suzukii (SWD) is gaining ground in the United States through the introduction of two wasps, Ganaspis brasiliensis (known as the samba wasp) and Leptopilina japonica (known as the ronin wasp). These wasps, which evolved in Asia alongside the SWD, have been approved for rearing and managed release by entomologists to counter the spread of the fruit fly.
Entomologists at Michigan State University (MSU) initiated a project in 2023, releasing 39,000 samba wasps in 30 fruit sites in Michigan. The wasps were recovered at least in five sites, demonstrating their survival capability and successful ability to attack SWD larvae. This outcome was enthusiastically welcomed by experts as it represents the first evidence of wasps' victory in the SWD lifecycle.
Professor Rufus Isaacs from MSU emphasized the significance of this success, highlighting that samba wasps managed to surpass the lifecycle and attack SWD, marking significant progress. Dr. Andrew Jones, a graduate student of Professor Julianna Wilson, studied the samba wasps' ability to survive Michigan winters, yielding promising results.
The research and government approval process for releasing the wasps was lengthy, but evidence indicates that the wasps are up to the task. Although less than half of the wasps survived the first winter, this is considered a positive sign.
The research also involved Professor Kent Daane from the University of California, Berkeley, who contributed to identifying samba and ronin wasps as potential effective parasitoids. The wasps have been found in nature in various regions of the United States and Canada.
While some researchers express caution about the current impact on SWD populations, there is confidence that over time, the effectiveness of wasps in controlling the fruit fly will increase. Ongoing monitoring and future releases of ronin wasps could significantly reduce SWD pressure at the beginning of the season in US fruit-growing regions.
Samba wasps in a container before release
Read the full article: Good Fruit Growers
Images: Good Fruit Growers
05 Aug 2024
The 2024 harvest was expected to be 20.9 million boxes, with a 12% increase compared to a year ago. The industry continues to pack greater quantities than expected and reached a peak in July 9th, with an overall volume that continues to appear above the five-year average.
20 Aug 2025
Ratafia Ciociara has received PGI recognition: a traditional cherry liqueur made exclusively in Frosinone, Lazio. Blending local wines and wild cherries, it offers a deep, authentic taste. Perfect as a digestif, in pastries, or for bold cocktails with an Italian twist.
16 Jan 2026
B.J. Thurlby, who passed away at age 60, led the Washington State Fruit Commission for over 25 years. As a true ambassador for Northwest cherries, he championed research, exports and grower education, leaving a deep mark on the U.S. and international fruit industry.
16 Jan 2026
Frutas de Chile has revised its 2025/26 cherry export forecast down by 15% due to adverse weather, with shipments expected to reach 110 million boxes. To support sales, the Cherry Ice and Snow Festival launches in China, blending cherries, lifestyle and Lunar New Year culture.
