2022 Entomology Update: Early June

Based on the previous year flight dynamics, it is expected this first codling moth (CM) generation will be active at least until the end of June. Pheromone traps are the most reliable method to assess the real pest pressure in an individual orchard and the best tool to help in deciding if and for how long insecticide treatments will be necessary.

To improve efficacy of codling moth pheromone traps they should be placed as high as possible within the tree canopy (See Figure 1). While this is the optimal timing for the second treatment against CM larvae, with products such as Altacor®, Besiege®, Delegate®, Exirel®, Verdepryn®, or Voliam Flexi® not every orchard will require third or more additional treatments. Insecticide application(s) against codling moth with insecticides listed above should also control tufted apple bud moth (TABM) and obliquebanded leafroller (OBLR).

In organically managed orchards, if needed, weekly applications of codling moth granulosis virus (CpGv) as in Cyd-X® or Madex HP® will provide good control of codling moth while applications of BT based products or Entrust® should effectively manage leafrollers.

Figure 1. (Left) Early season injury caused by codling moth on apples (Center) and sticky floor from pheromone traps for monitoring codling moth. (Right) Pheromone traps should be placed as high as possible in the tree canopy. Photos: Greg Krawczyk, Penn State

As of June 02, the flight of the first-generation Oriental fruit moth (OFM) adults appears to be completed around Pennsylvania, and OFM control is no longer effective, as most survived larvae are actively feeding under cover either inside fruit or growing shoots. Checking for wilted (injured) shoots on stone fruit or injured fruit on apples (Figure 2) should provide a good indicator of potential OFM pressure later during the season, as two or three more OFM generations will be active until October.

It is also too late to control plum curculio adults (PC). Most PC caused injuries are already present on fruit (Figure 2). With only a single PC generation per season, PC adults will re-emerge from pupae in the soil during mid-August only to feed for a short period inside orchards. The adults cause pin-point injuries on fruit, then migrate outside of the orchard for the winter and come back next spring.

Figure 2. (Left) Peach shoots and apple fruit injured by first-generation OFM larvae. (Center and Right) Apple fruit injured by plum curculio ovipositional scar. Photos: Greg Krawczyk, Penn State

If pear psylla control is required, then Admire® Pro, Actara® 25WP, or Assail® 30SG (plus a quart of summer oil) should be very effective for control of pear psylla nymphs. Other products such as Delegate, Exirel, Sivanto®, Movento®, Verdepryn, or Closer® should also be considered if multiple applications of insecticides will be needed as the season progress.

Brown marmorated stink bug (BMSB)adults are almost completely out of overwintering shelters. In order to prevent them from establishing in the orchard, if needed, a single application of effective insecticides such as Endigo®, Actara®, or Assail® should control both BMSB adults and nymphs. Each application will also control increasing spirea aphid populations and the soon arriving Japanese beetles.