Synopsis: The 2nd generation of San Jose scale emerged this week with first finds in black electrical tape and Vasoline fixed to tree limbs of infested apple at the HVRL. The application of contact insecticides and or growth regulators should begin at your first application window.
Codling moth continues to cause significant injury to Hudson Valley tree fruit this season. The 2nd generation hatch of CM larva continues this week requiring management as heavy rains have diminished residues.
Apple maggot flights are on the increase in regional traps with ideal soil moisture for high numbers of adult emergence. Timing, use of most effective materials, employing effective rates, reapplication of insecticides and incorporating resistance management strategies are becoming more important to obtain effective codling moth control.
36% of untreated Ginger Gold now have apple maggot injury.
San Jose Scale: If you had SJS on your fruit last season AND did not make applications against this insect during the pre-bloom or early post-bloom period, the window for applying an effective insecticide is now using a contact insecticide and will continue for about 5-6 weeks, requiring a second application in two weeks. If SJS is now showing up in the southern Hudson Valley with nymphs causing spotting of fruit, applications of effective insecticides should be made at the earliest application window. Choices available for SJS management include Admire Pro 4.6SC at (2.8 fl.oz./A) a feeding toxicant, Assail 30SG (8.0 oz./A) a translaminar feeding and contact insecticide, Centaur 0.7WDG (34.5 oz./A) and Esteem 35WP (4-5 oz./A) insect growth regulators; Imidan 70WP 70WS (2.13-5.75 lb./A), contact insecticide; the pre-mix insecticides Endigo ZC (5-6 fl.oz./A), Leverage 360 (2.4-2.8 fl.oz./A) and Voliam Xpress EC (6-12 fl.oz./A) include contact and feeding activity.
Centaur 0.7WDG acts to inhibit the synthesis of chitin (Class 16) working as an insect growth regulator (IGR).
Esteem 35WP, also an IGR, functions as a juvenile hormone mimic, inhibiting metamorphosis from one stage to another (Class 7).
These insecticides are most effective when directed against crawlers at first appearance yet have no contact toxicity and tend to act very slowly.
Assail (Class 4) is a broad-spectrum neonicotinoid that also is most effective when directed against crawlers as they emerge. The efficacy of these materials is improved by the addition of oil, however, Esteem 35WP and Assail can be used effectively without the use of oil. The OP Imidan 70WP and pyrethroids can also be used against the crawlers during emergence in back to back applications at 7-10 days.
Remember, rotating classes of insecticides for each generation will delay the onset of resistance.
Making multiple applications of the same class or same insecticide at a 7-10-day interval for the same generation is recommended.
Movento requires a two week window and will be ineffective for this early stage of emergence.
However, If you’re trying to clean up a robust population, Movento PLUS OIL or a penetrant such as LI700 at a penetrating rate should be applied along with a contact insecticide to manage this early stage of emergence. Our research suggests that the use of a single application of Movento + penetrant using the high labeled rate of 9 fl.oz./A provided very good commercial control of the pest.
Movento plus penetrant is also very effective against wooly apple aphid (WAA).
For organic tree fruit growers, oil is the best cure for SJS. Kaolin Clay, the active ingredient of Surround WP, has no efficacy against the emerging crawlers. Keep oil away from applications of sulfur used for disease management to avoid phytotoxicity to fruit and foliage.
Codling Moth: We are seeing the emergence of the 2nd generation of CM, requiring management in Hudson Valley pome fruit. Many of the regions orchards now have resident (endemic) populations of codling moth from infestations occurring in 2016. Assessing fruit injury by scouting for frass at the calyx and stem end of fruit, at this point in time, is critical for decision making and management.
Focus on specific blocks where specific variety fruit injury was observed last season. Remove suspect fruit and slice through the center to look for seed feeding indicating codling moth larva presence. If codling moth injury is observed in fruit, management is required to reduce further injury during 2nd generation larval emergence.
We have passed the window for use of pheromone trapping to capture the initial wave of second generation CM adults to establish on-farm biofix in the mid-Hudson Valley. As such, are too late to effectively control this second generation CM through mating disruption unless it was applied earlier in the season. The use of Rimon 0.83EC is most effective prior to egg laying, which too has come to pass and would be less effective applied for control of CM. We are now left with the remaining options for managing this insect using contact and feeding insecticides including granulosis virus.
In the mid-Hudson Valley, larval emergence will occur during the latter part of this week, requiring management in blocks with historical damage or adult trap capture exceeding >5 CM adults per week. Maintaining residue of effective insecticide on a 2 week schedule based on weather.
A number of products are available for use in New York State. In blocks of high fruit infestation from codling moth in 2016, a possible cause may have been the use of materials ineffective against the worm during the three generation emergence periods of the larval stage, most notably the 3rd generation in September. The possibility of frequently used insecticides slipping in efficacy is also a possibility.
This insect continues to re-emerge as a primary pest of apple throughout the world. And it can be argued that codling moth has historically been the greatest threat to tree fruit production due to its endemic orchard presence, constant exposure and development of cyclical resistance to insecticide programs. During the 2016 harvest we observed very high levels of fruit infestation in Hudson Valley apple, ranging from 2% to 40% injury in commercial production, bringing a level of uncertainty to the effectiveness of the materials in our toolbox.
Management: Presently we have standard ‘older’ classes of insecticides that include the Organophosphate, Carbamates, Pyrethroids and Pyrethroid pre-mixes that are still effective along with the Neonicotinoid Assail, Anthranilic Diamides that include Altacor and Exirel, and Spinosyns including organic Entrust and conventional insecticide Delegate.
An additional option is to apply a granulosis virus formulation at 200-250 DD 50°F. High moth pressure requires 2-3 sprays for the first generation, but in lower pressure orchards (with counts of less than 5 moths per trap per week), you can control CM with a single spray timed at 350 DD 50°F.
Codling moth granulosis virus formulations include Cyd-X, Cyd-X HP, Madex HP by Certis; Carpovirusine by Arysta LifeScience. Cyd-X 0.06SC is applied @ 0.25-0.4 qt/acre and Carpovirusine 0.99SC @ 0.25-0.4 qt/acre.
Codling Moth Granulosis Virus contains an insecticidal baculovirus, Cydia pomonella granulovirus, which is specific to the larval form of the codling moth, and is registered for use in apples, pears, and (Cyd-X only) plums. This biological insecticide must be ingested in order to be effective, after which the viral occlusion bodies dissolve in the larval midgut and release infectious virions.
These enter the cells lining the digestive tract, where they replicate; eventually, the other tissues are infected and the larva stops feeding within 3-7 days, and dies shortly thereafter. The decomposing larva disintegrates, releasing billions of new occlusion bodies, which may infect other codling moth larvae upon ingestion. No adverse effect to fish, wildlife or beneficial organisms has been observed; it has a low bee-poisoning hazard