BMSB 2nd Generation. Adult threshold exceeded in Mid-Hudson Valley. September 9th, 2024

Synopsis: Newly emerging nymphs and 1st generation adults have been on the increase, nearing or exceeding threshold throughout Orange and Ulster County. The early instar stages of Brown Marmorated Stink Bug (BMSB) Halyomorpha halys (Stål), newly hatched from eggs over the past three weeks, are making their way to traps and increasing in numbers throughout the state. All life stages along commercial blocks in mid-Hudson Valley orchard sites have been observed this past week.

Movement to apple foliage and fruit and fruit feeding is continuing in untreated orchards. Trap numbers of stink bug in combination with scouting for the insect in perimeter tree canopy should precede management during this time of BMSB population build-up. Review labels for pre-harvest intervals (PHI) when choosing materials as the most effective materials have 14 DTH constraints.

When thresholds are exceeded or stink bug become visible along the orchard edge, border row applications should begin. These should then be followed by alternate row, then whole orchard applications as movement of native and BMSB populations begin to migrate into orchards.

As stink bug are orchard edge opportunists, the majority of the injury to fruit will occur along the wooded orchard edge, 30′ to 90′ along the perimeter into the block of varieties highly susceptible. These include Golden & Red Delicious, Empire, Ruby Frost, and the last standing…Pink Lady. As fruit diminishes through harvest, BSMB funnel to the remaining fruit, which could be heavily injury in October through early November. 

Insecticides selected for whole orchard applications should also have strong efficacy for apple maggot,2nd gen. obliquebanded leafroller, and as we move into September, codling moth for which management may be required if a third generation arrives.Scouting is important to determine the insects’ presence and in the orchard.

Perimeter and alternate row applications (ARM) beginning at threshold may suffice under low population levels. As the insect is quite mobile through flight and crawling, its movement through the canopy will increase its contact with insecticide residue under ARM.

Overview:
The brown marmorated and native green stink bug are arboreal insects, residing in woodland habitat. However, when populations continue to rise through July into August, increasing numbers of adults and nymphs can be observed on tree fruit. his has occurred over the past two weeks. Increasing presence of the insects in trees will result in injury in peach, pear and apple rows bordering woodlands and hedgerows.

Nymphs ranging from 2nd to 5th instar of both species have been observed feeding on fruit along the orchard perimeter this week. This newly developing partial second generation will significantly increase BMSB population in woodlands.

As host quality from the arboreal woodland habitat declines, increasing migration to tree fruit is very likely through the end of August on through to the end of October. Increased scouting should be based on recent and upcoming Tedders trap captures. This will be especially important if weather turns dry with irrigated tree fruit becoming a favored host of BMSB as adults begin to feed more intensively as they prepare for their overwintering phase.

Monitoring: Remember that trap captures combined with scouting for the various life stages of the insect along the orchard perimeter rows should be the basis for insecticide applications. Unlike most other pests, we should not be using IPM thresholds based on stink bug feeding that results in fruit damage. SImply, the expression of the injury occurs 7-10 days or longer after feeding. As such,  you would have missed your opportunity to reduced injury if you postpone preventative applications while waiting on injury that has already occurred to become visible.

Use a conservative presence and trap threshold on through harvest. Finding a single BMSB or green stink bug in the tree canopy within 100′ of scouted perimeter row would be considered a conservative threshold (no data to support this). Driving along the orchard will likely spook the insects. You’ll need to stealth your way quietly around the orchard…its good exercise in the early evening or early cool of the morning. Green stink bug tend to remain low in the canopy while BMSB tend to move to the tops of the trees to feed requiring us to scout the entire canopy.

Management: When selecting insecticides for border row, alternate row and or whole orchard applications, you should consider constraints on your markets. If weather turns to drought, then longer residue based on the active ingredient minimum residue level (MRL) could become an issue, especially in EU and Israel markets. Review your options carefully with regards to harvest dates, PHI’s, re-application intervals and seasonal A.I. volume (Actara (Thiamethoxam).

When BMSB populations dramatically increase during late season, migration into orchards can be dramatic. BMSB have been known to funnel down to the last variety standing (such as the high value Pink Lady). In which case, applications in late October may be warranted!!

Applications of insecticides selected for whole orchard applications (such as northern Champlain region) should also have strong efficacy for apple maggot, obliquebanded leafroller and 3rd generation codling moth if CM infestations from 1st or 2nd generation are active, which may also require management (primarily in late August as we are outside this window in the mid-Hudson Valley).

One of the most effective tools for use to manage BMSB is the active ingredient bifenthrin in a number of formulations.

Bifenthrin has a 12 hr. re-entry interval, 14 day pre-harvest interval and a 30 day re-application interval.

Brigade WSB (Bifenthrin) is labeled for Pome Fruit in NYS. Do not apply more than a total of 0.45 lbs ai/acre per season post PF. Apply as necessary to maintain control using a minimum of 30‐day spray intervals, 14-day pre-harvest interval and a 12 hour REI.

What to do up to 7 days to harvest: Leverage 360 has a 7-day pre-harvest window and has been shown to have excellent efficacy against BMSB from research trials across university studies.

What to do within 7 days to harvest: Keeping BMSB from feeding on the fruit is at the crux of our stink bug management program as we near harvest. Killing the insect as it moves into the orchard and onto the fruit is the traditional method of crop protection and proven to be very effective. Yet limitations, based on the material pre-harvest intervals constrain their use near harvest. There are no effective pyrethroids, neonicotinoids or pre-mixed insecticide tools that permit their use within the 7-day to harvest window with very few options available during the days prior to fruit harvest.

A Novel Mode of Action: The development of newer classes of insecticides that produce an anti-feeding response in the pest provides an additional mode of action for BMSB management. Corteva insecticide Closer 240 SC  (classified as a Group 4C insecticide / neonicotinoid – 7 DTH) is available in the Northeast but not available in NYS. Yet Venerate XC (a microbial-based insecticide with multiple modes of action and O DTH) having anti-feeding activity against BMSB fruit feeding. The O DTH of Venerate provides BMSB management up to the day of harvest under high risk conditions (Data slides of efficacy trials).