By Grzegorz Krawczyk,
The third generation of codling moth (CM) and fourth generation of Oriental fruit moth (OFM) are continuing their flights and egg deposition in many orchards. While the CM flight should cease within the next 2 weeks, the OFM will continue its flight and egg deposition until at least mid October. Only on site monitoring of each individual pest will provide accurate information if and for how long control treatments are necessary. Applications of Altacor®, Belt®, Delegate®, Tourismo® or Voliam Flexi® or Voliam Xpress® should provide excellent control of CM and OFM. Codling moth granulosis virus (Cyd-X®, or Cyd-X HP) provides good control only of CM neonate larvae. Both Voliam products will also provide some control/suppression of brown marmorated stink bug.
Brown marmorated stink bug (BMSB) adults and nymphs are actively feeding in many orchards and areas around orchards. The numbers of BMSB adults and nymphs collected in traps monitored by our entomology program are very high, much higher than during the 2012 season (as of September 6). If BMSB nymphs are spotted inside any orchard, a control treatment is needed immediately. While adult BMSB can continuously move in and out from any orchard, BMSB nymphs are resident pests and will continue feeding on fruit until mid-October. The assortment of effective BMSB insecticide options is limited and includes pesticides with only a few distinctive modes of action: pyrethroids (IRAC Group 3A): Bifenture® and Brigade® (bifenthrin), Danitol® (fenpropathrin), and Warrior II ® (lambda-cyhalothrin); neonicotinoids (IRAC Group 4A): Actara® (thiametoxam), Assail® (acetamiprid), Belay® (clothianidin), Scorpion® and Venon® (dinotefuran); one carbamate product (IRAC Group 1A), Lannate® (methomyl) and some products including combinations of two different insecticide chemistries such as in Endigo ZC® (thiametoxam and lambda-cyhalothrin) or Leverage 360® (imidacloprid and beta-cyfluthrin).
While trying to limit the impact of BMSB on fruit, please remember about seasonal limits for the number of insecticide applications (and total of specific active ingredient) per season.
Although traps by themselves will not control BMSB, by capturing adults and nymphs, traps can be utilized as an effective warning system in orchards.
If wooly apple aphids are observed in the orchard, but BMSB is not a problem, application(s) of Movento®, Closer® or Diazinon® should provide effective control.
As the season progresses and 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. Similarly as during the last few years, during this second half of the season, some of the commonly used developmental models seem to be overestimating the pace of development for CM and OFM populations in some orchards. Therefore, such models are not very reliable indicators of the actual pest situation. Please use on-site monitoring as the main indicator in deciding if and when a pesticide application is necessary.