Insect Bytes for July 20, 2017

Pheromone traps are the best indicators for controlling CM and OFM. Detection of live BMSB nymphs in traps placed in orchards warrants an immediate insecticide application.
Insect Bytes for July 20, 2017 - News


Brown marmorated stink bug adult on apple. Photo: G. Krawczyk, Penn State

Second Generation Codling Moth and Oriental Fruit Moth

The flight of the second generation codling moth started recently in most orchards located in South-central PA. With the extended flight of the first generation codling moth (CM) which lasted until late June and the presence of all sizes of CM larvae still feeding inside the fruit, this second generation flight is expected to continue for a long time. According to the standard CM developmental model based on accumulation of degree days since the biofix, the timing for the control of this CM generation is occurring right now, however this forecast likely does not reflect the actual situation occurring in most orchards. The captures of male moths in the sex pheromone traps should remain the most important indicator to decide if and when CM control will be necessary. Since most of the neonate CM larvae normally enter the fruit in less than 24 hours after the egg hatch, it is very important to have an active residue of effective insecticide present on fruit when most CM eggs are hatching and fruit infestation is happening.

The status of the Oriental fruit moth (OFM) is somewhat similar, with the third generation OFM egg hatch already forecasted by the developmental model. However, the ability of OFM larvae to develop during the early part of the season on fruit and shoots of peaches and apples, is directly responsible for the current presence of various OFM developmental stages and adults in an orchard at the same time. Early season feeding on various food sources impacts the rate (speed) of OFM development, so at this time of the season, we frequently see overlapping generations and continuous flight of OFM adult moths from overlapping generations. As with the CM, the captures of male moths in sex pheromone traps should be the main indicator to assess the necessity for an OFM management treatment.

If mating disruption products are not used for the management of OFM or CM and usage of insecticides is necessary, applications of Altacor®, Delegate®, Exirel ®, Minecto Pro ® or Voliam Flexi® should provide excellent control. The active ingredients in Altacor, Exirel, Minecto and Voliam share the same mode of action, so if any of these products was used for the first CM generation control, only product(s) with a different mode of action should be used against the consecutive generation. If codling moth granulosis virus (as in Madex® HP or Cyd-X®) is planned for CM control, the first application should start right now and applications should be repeated at intervals no longer than 7 days until the end of the CM flight. Madex HP should also provide good control of Oriental fruit moth larvae.

Photo 1. Codling moth (left) and Oriental fruit moth (right) male moths in pheromone traps. Photos: G. Krawczyk, Penn State

Intensified Movement of BMSB into Orchards

We continue to find in and around orchards various instars of brown marmorated stink bug (BMSB) nymphs developing from eggs deposited by overwintering generation adults. The first summer adult BMSB are also expected to appear at any time. With the arrival of this generation, we expect an intensified movement of BMSB into orchards and more frequent occurrence of fruit injuries caused by this pest. The on-site monitoring still remains the best indicator for whether or not treatments targeting BMSB are necessary. The BMSB monitoring lures and traps from AgBio Inc., AlphaScent Inc., Sterling International, and Trece Inc. are commercially available either directly from the manufacturer, specialty stores or stores like Walmart, Lowe's or Home Depot. While low numbers of captured BMSB adults does not always validate the necessity for a treatment, a detection of live BMSB nymphs in traps placed in orchards warrants an immediate insecticide application.

The list of BMSB effective insecticide options includes products with only a few modes of action: pyrethroids (IRAC Group 3A) such as Bifenture® EC and 10DF and Brigade® WSB (the same AI, bifenthrin), Danitol® (fenpropathrin), and Warrior® (cyhalothrin); neonicotinoids (IRAC Group 4A) such as Actara® (thiametoxam), Assail® (acetamiprid), Belay ® (clothianidin), Venom® and Scorpion® (dinotefuran); and one carbamate product (IRAC Group 1A), Lannate® (methomyl).

Photo 2. Brown marmorated stink bug adults and fresh egg mass (left) (Photo by Hillary Morin) and freshly hatched BMSB egg mass with first instar nymphs (right), (Photo by Tom Hass)

Japanese Beetles still Present

Japanese beetles (JB) are still being frequently observed in many orchards causing injury mostly to foliage of trees, but also feeding on mature stone fruit. Materials recommended for the control of brown marmorated stink bug should also provide effective control of JB. If the control of BMSB is not necessary, and only JB needs to be controlled, neonicotinoid insecticides OR carbaryl (Sevin®) should provide good control of JB.

Tufted Apple Bud Moth and Obliquebanded Leafroller Control

The best timing for control of tufted apple bud moth and obliquebanded leafroller is expected within 2 weeks--it is still too early to control TABM and OBLR. The best timing to manage those two pests, if present in the orchards, will be sometime within the next two weeks, most likely in early August. Products listed for the control of CM and OFM, except Cyd-X and Madex HP, should also provide effective control of leafrollers.

Photo 3. Tufted apple bud moth (left) and obliquebanded leafroller adult moths (right) in the pheromone traps. Photo: G. Krawczyk, Penn State

The insect pest control updates presented are for South-central Pennsylvania based on observations in Adams County. To view the insect hatch and trapping data for all major insect pests, please visit the Penn State Fruit Research and Extension Center (FREC) website. For control recommendations, refer to the Insect and Mite Control Toolbox.