Insect Bytes for August 10, 2017

The flights of the second generation codling moth (CM) and third generation oriental fruit moth (OFM) continue in most Pennsylvania pome fruit orchards.
Insect Bytes for August 10, 2017 - News


Brown marmorated stink bug adult and nymphs on corn. Photo: G. Krawczyk, Penn State

Only the on-site CM and OFM monitoring will provide accurate information if and for how long control treatments are necessary to manage these two internally feeding fruit pests. Applications of Altacor® (5d PHI on pome and 10d PHI on stone fruit), Delegate® (7d PHI on pome, 7d PHI on plums, 1d PHI on peach and nectarines) or Exirel® (3d PHI on pome and stone fruit) should provide excellent control of CM and OFM larvae. The insecticides listed above as well as Intrepid ® (14 d PHI on pome, 7d PHI on stone fruit) will also provide excellent control of two leafroller species, tufted apple bud moth and obliquebanded leafroller also present in orchards at this time of the season.

Organically approved, codling moth granulosis virus (CpGv) containing products Cyd-X®, Cyd-X HP provide good control of CM neonate larvae while Madex ®HP additionally should also control OFM larvae. Organic formulation of spinosyns (Entrust®) and product containing Bacillus thuringiensis such as Dipel® should provide effective control of leafrollers.

Codling moth injured apple fruit (left) and adult moth in pheromone trap (right). Photo: G. Krawczyk, Penn State

Oriental fruit moth injured peach fruit (left) and adult moths in pheromone trap (right). Photo: G. Krawczyk, Penn State

Brown Marmorated Stink Bug (BMSB)

All stages of brown marmorated stink bug (BMSB) including young summer adults are being observed to migrate into stone and pome fruit orchards. The typical symptoms of BMSB feeding include an internal corking under the skin of fruit and deformation of fruit. Unfortunately, these symptoms are usually not clearly visible on fruit for about 10 to 14 days after the actual feeding, making it difficult for immediate detection. On peaches, due to relatively short time left to harvest, the BMSB control may be needed only on the late maturing cultivars. However, this approach can not be utilized on apples. Due to possible longer storage time for harvested fruit which makes the stink bug caused injuries more visible, if any BMSB stage, but especially nymphs, is being observed in the orchard, then insecticide based control is needed immediately. While the presence of BMSB adults indicates possible fruit injury and maybe deposition of new eggs, the presence of nymphs means extensive and long lasting feeding of young stink bugs on fruit, and each individual feeding site equals injury.

At this time of the season, the commercially available BMSB traps baited with BMSB lures are very effective in detecting and capturing all mobile stages of BMSB. For the best results BMSB traps should be placed in the orchard rows bordering most likely source of migrating stink bugs such as woods, soybean or corn. However, as effective as the traps are in detecting migrating BMSB, they will not provide control of the bugs and should be treated only as an "early detection system". 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.

Brown marmorated stink bug adults on peach fruit (right) and apple fruit injured by BMSB (left). Photo: G. Krawczyk, Penn State

The list of effective insecticides options for the BMSB control is limited and includes products only with few distinctive modes of action: pyrethroids (IRAC Group 3A): Bifenture® EC and 10DF (14d PHI) and Brigade® WSB (14d PHI), Danitol ® (14d PHI on pome, 3d PHI on stone fruit), and Warrior ® (21d PHI on pome, 14d PHI on stone fruit); neonicotinoids (IRAC Group 4A): Actara ® (35d PHI on pome, 14d PHI on stone fruit)), Assail ® (7d PHI), Scorpion® and Venon ® (3d PHI); one carbamate product (IRAC Group 1A), Lannate® (14d PHI on apple, 4d PHI on peach), and some products including combinations of two different insecticide chemistries such as in Endigo® (35d PHI on pome and 14d PHI on stone fruit) or Leverage® (7d PHI on pome and stone fruit).

No effective, organically approved product is available for sufficient direct control of BMSB. While trying to limit the impact of BMSB feeding on fruit, please remember about seasonal limits for the number of insecticide applications per season.

Insecticides used for the control of BMSB should also provide some control of other potential pests in the orchards, however the decision of what product to use and when it should be used, should be based on the local monitoring of various pests presence and the actual pressure from individual pest species.

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 .