WNC Orchard Insect Populations for July 3, 2018
Depending on location, codling moth degree-day accumulations since biofix range from about 1300 in Henderson County to almost 1600 in Lincoln County. Timing of first insecticide applications is recommended at about 1400 DD. Under low population densities, a single application between 1400 and 1500 DD will provide sufficient protection, while two successive applications at 14-day intervals are recommended if pheromone trap captures are exceeding 5 to 7 moths/trap or there is evidence of first-generation damage. Depending on population abundance, codling moth could be an issue for another two to three weeks.
The normal early July complex of indirect pests continue to be observed throughout the region, including Japanese beetles, European red mite, apple aphids, and potato leafhopper. In most instances a single application of a miticide for ERM and a neonicotinoid for Japanese beetles, aphids and leafhoppers has provided excellent control.
Looking ahead to the next few weeks, first-generation adult brown marmorated stink bugs are expected to begin emerging in about a week in lower elevation piedmont locations, and in about two to three weeks in higher elevation orchards (>2000 ft). Typically it is this generation of adults that can potentially cause the greatest levels of damage, particularly during the main emergence period in August. To date, BMSB numbers have been quite low throughout the region, but we have pheromone traps set up in numerous locations throughout the region. We will keep you updated on trap captures in the coming weeks.
Dinotefuran (Venom, Scorpion) and Bifenthrin (Bridage, Bifenture) Section 18 Approved for Control of Brown Marmorated Stink Bug
The EPA has approved the NCDA&CS request for Section 18 emergency use exemptions of the active ingredients dinotefutran and bifenthrin on apples and peaches to control brown marmorated stink bug. Dinotefuran products available for use include Venom (Valent USA) and Scorpion (Gowan Company), while bifenthrin products include Brigade (FMC Corp.) and Bifenture (United Phosphorus, Inc.). This is a regional Section 18 approval for these materials that includes most of the tree fruit production states in the eastern US. Dinotefuran has a 3-day PHI, and a maximum of only two applications per season (Venom and/or Scorpion) may be applied. Product labels must be on hand when using these products, and can be downloaded below:
Learn more about southeastern apple insect pests at the Apple Insect Management page.
2018 Average Weekly Trap Captures*
|Insects per trap|
|Oriental Fruit Moth||15.7||19.3||15.7|
|Tufted Apple Bud Moth||1.0||0.0||0.0|
|Brown Marmorated Stink Bug (commercial – mountains)||0.5||0.4||0.3|
|Brown Marmorated Stink Bug (commercial – upper piedmont)||1.0||0.6||1.3|
|Brown Marmorated Stink Bug (research – unsprayed)||2.3||0.8||1.0|
|Spotted Tentiform Leafminer||12.0||30.0||0.0|
|Lesser Peachtree Borer||15.0||13.5||7.0|
|San Jose Scale||12.5||0.0||2.5|
*Note that averages presented here are intended only to illustrate the timing of insect emergence and fluctuations in population activity, and not as general indicators of population levels. Some orchards included in these averages have significantly higher or lower populations than most commercial orchards in the area, resulting in averages that are sometimes skewed from what is typical. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.
2018 Accumulated Degree Days
|Codling Moth||Apr 30||936||1124||1323|
|Oriental Fruit Moth||Apr 2||1418||1636||1876|
|Tufted Apple Bud Moth||May 4||1099||1317||1556|
|About degree-day models: The degree day (DD) models predict adult emergence and egg hatch of each generation. They do not predict the intensity of populations, which can be assessed by using pheromone traps. Hence, the models should be used to help gauge the time period when control is most likely needed, and pheromone traps provide information on the need for and frequency of insecticide applications. For full details, read “IPM Practices for Selected Pests” in the Orchard Management Guide.|
ORIENTAL FRUIT MOTH:
TUFTED APPLE BUD MOTH: