SWD Update Week of 7/8 – Continued trap captures across NY State

Spotted wing drosophila (SWD) trap captures continue to be reported in many locations throughout NY state over the past few weeks. Fewer sites reported this week, as sustained trap capture has been reported in most locations. In many places, trap counts continue to be low. In some locations populations have escalated quickly. No new first captures were reported this week (7/8).

New first trap captures were reported this week in St. Lawrence county. First trap capture dates were similar for 2024 (June 11) and 2023 (June 13) which is unexpected and different than other sites. In many locations trap captures have been 1-2 weeks earlier than average this year likely due to the warm, wet weather. This is especially noticeable compared to last year (2023) in which the cool, dry spring resulted in trap captures later than average.

Cumulative SWD Trap Captures at Monitoring Locations in NY State

First captures were reported:

• The week of 5/27 in Albany, Dutchess and Suffolk Counties.
• The week of 6/3 in Clinton, Columbia, Schuyler, Washington, and Ontario Counties.
• The week of 6/10 in Delaware, Essex, Niagara, Tioga, Tompkins, Wayne
• The week of 6/17 in Chenango
• The week of 6/24 in Monroe
• The week of 7/8 in St. Lawrence 

In most locations, sustained trap capture was reported the following week (sustained + two consecutive weeks of positive trap captures). Traps are taken down in some locations after 2 or 3 consecutive weeks of captures. In other locations they are used by growers to estimate pest pressure over the course of the season. While there is currently no data-driven recommendations on thresholds to guide pesticide applications, work is being done to test this at labs across the country, including Dr. Greg Loeb’s lab at Cornell AgriTech in Geneva.

As mentioned our first update for 2024 summarizing SWD monitoring, first captures are somewhat earlier than has been reported in the past. This is especially true compared to last season (2023), in which first trap captures for many locations were recorded nearly two weeks later than average. This highlights the need for site and season specific monitoring efforts to initiate management programs at the appropriate time.

Under the correct conditions, populations of SWD can increase rapidly. First and sustained trap capture has been reported in the majority of monitoring locations at this time, although in some locations SWD has not yet been detected in traps. In most places, numbers are low and slowly increasing. But in some locations populations have increased dramatically. In other locations, populations have declined, likely suppressed by insecticide applications. The following graph shows at sites across NY State from the week of May 27 to July 1, showing increase in the overall number of insects captured per site.

Weekly SWD trap captures by location across NY

Weekly SWD trap captures by location across NY

Thank you to all of our collaborators for servicing SWD traps across the state!