Traps captures of the adult brown marmorated stink (BMSB) continue to climb in Orange, Ulster and Dutchess Counties. However, from Columbia county north to the Canadian border and west to Buffalo few adults of the pest have been observed in Tedders traps to warrant significant management concerns. A word of caution on focusing only on BMSB. As the dry weather continues in September with only 1.67 inches to date for the month, (6.87 inches is the Sept. average) the likelihood of green stink bug feeding on fruit will also increase as BMSB lures are relatively ineffective at monitoring green stink bug. In orchards with historical injury to fruit from this pest, scouting should be continued as future management may be required.
Damage in many orchards appears highest in red delicious. The interior of the tree and low hanging fruit are often most favored by native stink bug while BMSB prefer fruit at the tops of the trees. Here is an example of a fruit that appeared sound until it was spun, showing the damage on the side facing the tree interior.
Upon close inspection of the fruit the lenticels (gas exchange openings in the fruit surface will appear considerably larger then the feeding sites of stink bug (Image below). Using a hand lens at 20x may also show small feeding tubes rising from the feeding site but are easily removed when the fruit is rubbed.
If whole orchard applications have been made it is important that orchard perimeter applications continue on a tight program with less effective insecticides applied on a 5-7 day program. As the pre-harvest interval (PHI) is critical, place your longer interval applications sooner (Bifenture EC @ 14d PHI) with low PHI materials made closer to harvest (Leverage @ 7d PHI). Bifenthrin, the active ingredient in Bifenture and Brigade appears to be the most active insecticide we have available to NY tree fruit growers. If Bifenthrin has not yet been employed in your orchard (having a 30 re-treatment restriction) AND you have the ability to use it on susceptible varieties nearing harvest (14d PHI), then it would be the best option at this point in time.
By targeting the orchard blocks that have wooded border first, growers should consider spraying from the perimeter of the orchard into the block (a border or perimeter application). As the concentration of injury will occur within 90′ along the wooded boarders, concentrating your efforts along the edge would be an economical and viable option for management of the BMSB at this time. If BMSB adults are found within the orchard, then alternate row middle or whole orchard applications will likely be required.
At greatest risk are the NY counties of Dutchess, Orange, and Ulster awith a few sites in Columbia that need monitoring. Scouting in Red Delicious, Golden Delicious, Honeycrisp, Ruby Frost and Pink Lady should be ongoing through harvest. Thus far, the red delicious appear to have suffered the largest losses from SB feeding injury.
The list of the most effective insecticides for BMSB management is found above. NYS labeled insecticides effective for use against the BMSB are available in four major classes including pre-mix formulations.
Endego ZC, a combination of Thiamethoxam (A.I. in Actara) and Lambda-cyhalothrin (A.I. in Warrior) is very effective, however, you have in New York State, a total of 0.188 lb. a.i. of thiamethoxam-containing products per acre per growing season with the PHI requirement of 35 days. Lannate, a carbamate, is also very effective but with relatively low residual and 14d PHI. Danitol, a pyrethroid is very effective with residual for 7d and a 14d PHI.
Danitol is likely to be the best choice during the latter part of the season as its short pre-harvest interval and efficacy is a good fit. It is not as effective as Bifenthrin, however, it’s a very good choice for management of BMSB in peach as it has a 3-day PHI, strong efficacy, especially as a knock down insecticide, and also works well against the native stink bugs.
Be mindful that the residual against this pest is relatively short lived, requiring vigilance in trapping and scouting 4 days post application. BMSB that have a knock down response when exposed to the lesser effective pyrethroids with be back on their feet in three days (if ants don’t get them) and back in the trees feeding again.
Regardless of the product used, a maximum of 0.08 to 0.2 lb[AI]/acre/season will be allowed, with no more than 0.5 lb a.i./acre applied per year with multiple applications made at a minimum of 30 day intervals; a restricted entry interval (REI) of 12 hours and pre-harvest interval (PHI) of 14 days must be observed. When applying either of these materials for BMSB control on apples, peaches, or nectarines, growers must have possession of the Section 18 label.