‘Summertime….and the living is easy’; with exceptions made for farmers and fruit growers.
The second of three generations of codling moth this season is beginning its flight with egg laying and larval hatch expected within the next 8 days. Now that Apple Maggot have emerged and reached threshold in some blocks, the first application for Apple Maggot will likely begin tomorrow morning. Japanese beetle have been increasing in numbers with fruit feeding observed in Ginger Gold this morning and the increasing presence of wooly apple aphid will also need to be addressed in many orchards.
Codling moth (Order Lepidoptera, Family Tortricidae): Our Scouting Report pheromone trap captures show increasing flight of the adult males beginning late last week. As of Monday July 11th, the degree day developmental model for 2nd generation codling moth predicts adult emergence at 6%. The adults are now mating, with egg laying and larva hatch to begin in the mid-Hudson Valley orchards within the next 7-8 days depending on predicted temperatures.
Each orchard is unique. To determine the presence of CM in your orchard hang at least 1 trap per 10 acre orchard block at the top of the canopy, specifically in blocks in which historic internal lep. damage has occurred. Cornell suggested trap threshold for CM: If > 5 codling moths are caught per trap per week using standard lures, there can be problems in fruit from the next generation. High trap counts are a warning to prepare for an application. If trap counts continue to exceed threshold throughout the season, maintain insecticide coverage on a 2 week interval.
When scouting for fruit injured from the previous 1st generation in early June, look for frass at the calyx end of the fruit and red ringed holes along the cheek and shoulder with frass. If you cut open CM injured fruit, you are likely to find the seed partially eaten nestled in dark brown frass. Core feeding from lesser apple worm and Oriental fruit worm will not result in seed feeding. San Jose scale also produce a red ring from feeding, however, there will be no hole or frass from SJS. If populations of CM reside within the orchard or if adults migrate in from abandoned trees along the borders, they are likely to give rise to damaging populations this week. Trapping in your orchard is the best way to determine presence of the insect.
Generally, we are seeing very high incidence of CM injury in untreated and organic treated fruit this season. Red delicious typically seem to be a favored variety. We have been hearing from many New England growers regarding increased fruit injury from internal worms over the past few years.
Since apple maggot has now reached threshold in high pressure blocks, the selection of management tools to control both codling moth and apple maggot are in order. The neonicotinoid Assail is very effective against both insects.
Assail used only for CM management can be used effectively at lower rates (4-8 oz./A). However, for AM management, rates should be at the 8.0 oz./A. Restrictions for Assail include:
• Do not make more than 4 applications per season.
• Do not apply more than once every 12 days.
• Do not apply less than 7 days before harvest (PHI = 7 days).
• Do not exceed a total of 0.60 lbs. active ingredient (32.0 ozs. product) per acre
per growing season.
Imidan (Phosmet) is also very effective against both insects at 2 1/8 to 5 3/4 lbs/A.
The pyrethroid group and pre-mix formulations with a pyrethroid will also perform well against this complex.
On some farms in the mid-Hudson Valley, including Highland, Milton and Marlboro, consideration to control the stink bug complex, including the Brown Marmorated Stink Bug (BMSB) would employ a pre-mix or Bifenthrin to manage this additional pest.
We observed the first emergence of Japanese beetle, Popillia japonica last week (5th of July). However the emergence has been in many sites lackluster compared to previous growing seasons with relatively few beetles causing damage to fruit trees up to this point.
Many of the insecticides used to manage apple maggot (such as the OP’s pyrethroids, Delegate & Entrust) will impact feeding to foligae and fruit by the beetle complex.