Synopsis: The next cover application on apple should be targeting the lepidopteran complex. Codling moth (CM) is winding down and obliquebanded leafroller (OBLR) is at >50% emergence. Scouting observations for 1st generation codling moth include frass evident in apple with larval feeding on the seed cavity, the 1st generation San Jose scale causing injury to apple from ineffective control. Dogwood borer (DWB) larva will be emerging over the next few weeks and management using directed trunk applications should be considered if DWB has been a perennial problem.
Overview: At this point in the season we are nearing the end of 1st generation codling moth emergence (CM) with obliquebanded leafroller (OBLR) emergence continuing. Targeted applications of effective insecticides against these two pests should be strongly considered this week to follow-up on initial applications against OBLR and CM.
Other insects on the near horizon are:
* Apple maggot, likely to emerge over the next few days after the rains
* Dogwood Borer hatch
* Brown marmorated stink bug egg laying in stone and pome fruit
Many of the insecticide choices (Delegate, Altacor…) are effective against both lepidopteran pests. However, a few insecticides, such as the Bt products, and very effective against OBLR yet weak on CM.
Codling moth; Order Lepidoptera, Family Tortricidae (CM): The end of the first generation CM is at hand with lowering trap captures observed over the past week. The model to predict the 2nd generation of codling moth management uses 1260 DD (base 50°F) after 1st generation biofix (on May 12, HVRL) to determine timing for 1st larval hatch. Management will include a follow-up application 2 weeks later. The 2nd generation of codling moth are predicted to emerge in mid-July in Highland depending on temperature over the next two weeks. We’ll keep you updated on CM emergence next week.
To determine the presence of CM in your orchard (for 2nd generation) hang 1 trap per 10 acre orchard block at the top of the canopy, in blocks where 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 management. If trap counts continue to exceed threshold throughout the season, maintaining insecticide coverage on a 2 week interval should be strongly considered.
When scouting for fruit injured from this pest during the 1st generation, which began in early June, look for a red bulls eye with a entry hole, red ringed holes along the cheek and shoulder likely to contain frass, or frass present in the calyx end of the fruit. San Jose scale also produce a red ring from feeding, however, there will be no hole or frass from SJS fruit feeding. Instead, the developing scale insect will be easily wiped off when rubbed, leaving a white dot at the center.
If you cut open CM injured fruit, you are likely to find the seed fed upon. Core feeding from lesser apple worm and Oriental fruit worm will not result in seed feeding. Management for this level and stage of damage is ineffective and can not be controlled now. 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 beginning mid-July at the onset of 2nd CM generation.
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. We have heard from New England growers regarding increased fruit injury from internal worms over the past few years with quite a few Hudson Valley growers in 2016 finding CM damaged fruit, likely from the uncommon 3rd generation we experienced last season.
Since apple maggot is not yet at threshold in high pressure blocks, the selection of management tools to control both codling moth and upcoming apple maggot should be considered for use next week to ten days out. A number of options are 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. However, in high temperatures (>80F), detoxification of pyrethroids increases significantly, causing reduced effectiveness and possibly increased fruit injury.
Brown Marmorated Stink Bug (BMSB): Orchards in the mid-Hudson Valley, including Highland, New Paltz, Milton and Marlboro, have observed BMSB nymphs in apple. Orchards with establishing BMSB populations should consider managing Brown Marmorated Stink Bug (BMSB) with a full block by block application or closely timed alternate row application. As we have seen few adults BMSB to date, its likely the native complex of green sting bug, moving from woodlands or the brown stink bug from broad leaf hosts as they dry down, would move to irrigated apple if drought conditions prevail. Danitol has been a good choice in these situations as it also controls AM and 2nd generation CM. However, as we move toward August, BMSB has often been the culprit of damage to fruit near harvest. In this case a pre-mix or Bifenthrin to manage this additional pest should be considered as 10 adult per BMSB trap reaches threshold indicated on EDDMaps/BMSB.