Growing Season Updates
Weekly Insect Bytes
The insect pest control updates presented below are for the south-central part of Pennsylvania based on observation in Adams County, PA.
Current pest status:
The second generations of tufted apple bud moth and obliquebanded leafroller are at the end of their respective egg hatch periods. However, if young larvae were not controlled, they will continue to feed on maturing fruit until harvest. Some late TABM or OBLR moths may still be around for the next few weeks, but no new generation of adult moths will be active this year. Although the captures of codling moth and Oriental fruit moth adults also appear to be on the decline, it will only be the codling moth, which will cease its activity within the next few weeks. Unfortunately, the fourth generation of OFM is likely to still be present in orchards during September and into October. Only site specific monitoring of each individual pest will provide accurate information if, and for how long control treatments are needed. Please use the on-site monitoring as the main indicator in deciding if and when the pesticide application is necessary. If brown marmorated stink bug also will need to be controlled during September and/or October, most products directed against BMSB should provide some limited control of OFM larvae as well, however, the efficacy of most products recommended for BMSB control is not very high against OFM larvae. If specific OFM control is necessary, applications of Altacor or Delegate remain the most effective tools to control this pest.
Older nymphs and adults of brown marmorated stink bug (BMSB) are being observed in and outside of orchards with some orchards also reporting fruit injured by BMSB. If soybean plants are planted around orchards, the edges of the fields provide an excellent area for visual detection of the presence of BMSB nymphs and adults. BMSB monitoring traps placed on trees located on the border of woods as well as traps placed in the first row of orchards, which sparsely collected any stink bugs for most of the current season, now are collecting many nymphs and adults. Also, similar increase in BMSB numbers are observed on sites already harvested such as cherry blocks or early peaches, which did not see any insecticide applications for a long time. Interestingly, during on-going field observations (through the early September), we are detecting brown marmorated stink bugs mostly on the edges of orchards bordering with woods but a much lower BMSB numbers on crops such as soybean or corn. Since not every orchard will experience the same pressure from BMSB, cautious scouting and monitoring of the vegetation surrounding an orchard should be very helpful in deciding if special stink bug control treatment(s) is necessary. It is important to remember the absence of stink bugs during the season, does not guarantee they will not become abundant in the orchard around the harvest time. BMSB is not an orchard resident pest and whatever management tactics were utilized to control BMSB during the season in any particular block, cannot guarantee or prevent new individuals from infesting/re-infesting the site just prior to the harvest.
Commercially available BMSB traps baited with BMSB lures are very effective in detecting and capturing all mobile stages of BMSB present in orchards. For the best results BMSB traps should be placed in the orchard rows bordering possible source of migrating stink bugs such as woods, soybean, or corn. As effective as the traps are in detecting migrating BMSB, they will not provide control of the bugs and should be treated only as an “early detection system”. Commercial BMSB lures and traps are available from Ag-Bio Inc. (http://www.agbio-inc.com/dead-inn-pyramid-trap.html,Phone: 877-268-2020) and Sterling International, Inc. (http://www.rescue.com/product/reusable-outdoor-stink-bug-trap, Phone: 509-343-3625).
The list of effective insecticide options for controlling BMSB is limited and includes products only with few distinctive modes of action: pyrethroids (IRAC Group 3A): Bifenture 10DF and EC formulations (14d PHI) and Brigade WSB (14d PHI), Danitol (14d PHI on pome, 3d PHI on stone fruit), and Warrior (21d PHI on pome, 14d PHI on stone fruit); neonicotinoids (IRAC Group 4A): Assail (7d PHI), Scorpion and Venon (3d PHI); single carbamate product (IRAC Group 1A) Lannate (14d PHI on apple, 4d PHI on peach), and some products including combinations of two different insecticide chemistries such as Leverage (7d PHI). While trying to limit the impact of BMSB on fruit, please remember also about seasonal limits for the number of insecticide applications per season.
As the season progresses and the trees become bigger, often the volume of used water per acre should be adjusted (increased). Even the most efficacious pest management products will not work if the spray coverage is not sufficient.
Prepared by Dr. Greg Krawczyk, PSU Department of Entomology, Fruit Research and Extension Center, Biglerville, PA.
Weekly update information on trap counts for Codling Moth, Obliquebanded Leafroller, Oriental Fruit Moth, Redbanded Leafroller, Spotted Tentiform Leafminer, and Tufted Apple Bud Moth.
Weekly egg hatch models for Apple Maggot, Codling Moth, Obliquebanded Leafroller, Oriental Fruit Moth, Spotted Tentiform Leafminer, and Tufted Apple Bud Moth.
- Fact sheet on Apple Scab
- Fact sheet on Cedar Apple Rust
- Fact sheet on Cherry Leaf Spot
- Fact sheet on Fire Blight
- Fact sheet on Sooty Blotch and Flyspeck of Apple
Carbohydrate Model for Precision Crop Load Management
To adapt the carbohydrate models for your own orchard site:
- Visit the NEWA website
- Go to the pull down menu under Crop Management and highlight Apple Carbohydrate Thinning
- Click on the leaf on the map closest to your site
- Click continue
- Enter your Green Tip Date and Full Bloom Date then hit the green Calculate button
Special Notes for Tables
- Values beginning with June 6, 2014 and thereafter are estimated based upon weather forecasts. If weather conditions change from what was predicted then you should take this into consideration.
- The 4 Day Average Balance values are derived from the current day Balance and the next 3 days to account for how the trees may respond based on predicted weather.
- The model is only as good as the predicted weather forecast. If the weather changes dramatically from the forecast recheck the model.
- Bud break and bloom dates are from grower evaluations of their orchards.