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
25 Jul 2024
The Belgian study focused on sweet cherry trees and observed the interaction between bumblebees and honeybees. The presence of bumblebees, particularly wild queens, was found to significantly influence honeybees’ behavior; they increased the row-switching frequency by ten times.
05 Mar 2024
Youfu Zhao recommends pruning in summer whenever possible and switching from sprinkler to drip irrigation to keep the orchard drier. For larger trees, it is possible to cut back the cankers, Zhao said, but this is fatal for young trees.
09 Feb 2026
In 2026, cherry emerges as a leading beverage flavor driven by nostalgia, natural colors and functionality. From dark sweet cherry to functional sodas, brands and consumers embrace an iconic, versatile and visually striking taste worldwide across global markets.
09 Feb 2026
Sweet cherry nutrition management in Chile is crucial for reserve accumulation supporting spring growth. Post-harvest applications of nitrogen, potassium, calcium and micronutrients enhance photosynthesis, tree vigor, fruit set and overall fruit quality.
