WNC Orchard Insect Pest Populations – May 26, 2021

— Written By and last updated by

Tractor in orchardMay 25, 2021

As has been the case for the past several weeks, codling moth remains the greatest threat throughout the region, although low populations make the risk of damage low in many orchards. Now is also a good time to begin scouting for secondary pests, including European red mite, aphids and leafhoppers.

Codling moth: Degree-day accumulations range from about 400 in Henderson County to 650 in Lincoln/Cleveland County. In the lower elevation orchards (i.e., Lincoln/Cleveland), first generation flight should decline over the next week or so. In Henderson County (and orchards at a similar elevation of about 2000 ft), we will be entering the main flight and egg-laying period of the first generation. In orchards being managed as if full crop, the next 7 to 10 days will be an important time to monitor populations, or apply an insecticide if not monitoring.

In lower elevations where tufted apple bud moth (TABM) is a concern, an insecticide applied anytime during the next two weeks is good timing. In Henderson County, the window for control of TABM will not begin for another 7 to 14 days.

Secondary Pests:  While it may seem early for European red mite, in orchards with high populations it is not unusual for mites to be observed by late May. We are also on the early side of potato leafhopper and green apple aphids, but a few leafhoppers, although too low to justify treating, were observed in our plots yesterday. Finally, in our research plots where rosy apple aphid (RAA) was not controlled early in the spring, aphids are continuing to spread. If RAA-curled leaves are observed in orchards, these leaves should be checked for the presence of live aphids. As temperatures warm, RAA populations will decline.


Learn more about southeastern apple insect pests at the Apple Insect Management page.


2021 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
May 10 May 17 May 24
Codling moth  4.5 2.5 5.5
Oriental fruit moth 11.5 3.0 7.0
Tufted apple bud moth 2.0 10.0 22.0
Redbanded leafroller 0.0 0.0 0.0
Obliquebanded leafroller 0.0 0.0 8.0
Lesser appleworm 0.0 0.0 12.0
Apple maggot (abandoned and research orchards) set
Brown marmorated stink bug (commercial) 1.0 2.0
Brown marmorated stink bug (unsprayed) 1.0 0.5 0.5
Spotted tentiform leafminer 0.0 0.0 0.0
Dogwood borer 1.0 10.0 21.0
Peachtree borer 0.0 0.0 0.0
Lesser peachtree borer 29.0 33.0 42.0
San Jose scale 0.0 0.0 0.0

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.


2021 Accumulated Degree Days

HENDERSON COUNTY
May 10 May 17 May 24
Codling moth (Biofix: April 10)
243 298 395
Oriental fruit moth (Biofix: March 27)
467 550 681
Tufted apple bud moth (Biofix: April 30)
108 191 323

About degree-day models


2021 Pest Trends (click to enlarge)

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Additional Resources

 

Written By

Jim Walgenbach, N.C. Cooperative ExtensionDr. Jim WalgenbachProfessor & Extension Entomology Specialist (Fruits / Vegetables) Call Dr. Jim Email Dr. Jim Entomology & Plant Pathology
NC State Extension, NC State University
Updated on May 25, 2021
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