WNC Orchard Insect Pest Populations – June 29, 2021
Codling Moth: Except for second-generation codling moth in lower elevation orchards (less than about 1200 ft elevation), insect activity remains low at this time. In the Cleveland/Lincoln County area about 1475 DD have accumulated since biofix, and now is the optimum timing for control of the second generation.
Remember that good resistance management practices call for using an insecticide with different modes of action against the first and second generations. The two most effective groups remain MOA group 28, the diamides (i.e., Altacor, Verdepryn, Voliam Felxi, Besiege), and MOA group 5, the Spinosyns (i.e., Delegate). Hence, if a diamide was used against the first generation, Delegate should be used against the second generation. Alternatively, if Delegate was used against the first generation then a diamide should be used against the second.
In Henderson County and other locations of similar elevation (≥2000 ft), only about 1050 DD have accumulated since codling moth biofix. These areas are still about two weeks from the need for an insecticide targeting the second generation.
Aphids, Leafhoppers and Mites: With shoot growth foliage now hardening off, leafhoppers and green aphid populations are declining and insecticidal control should no longer be necessary. Also, if European red mites have not developed to threshold levels by the end of June, they usually will not be an issue the remainder of the year. However, with increased pyrethroid use for brown marmorated stink bug in recent years, it would be wise to continue to scout for this pest.
Learn more about southeastern apple insect pests at the Apple Insect Management page.
2021 Average Weekly Trap Captures
|Insects per trap|
|Jun 14||Jun 21||Jun 28|
|Oriental fruit moth||17.0||34.0||36.0|
|Tufted apple bud moth||2.0||4.0||1.0|
|Apple maggot (abandoned and research orchards)||0.0||0.0||0.0|
|Brown marmorated stink bug (commercial)||1.0||1.8||1.7|
|Brown marmorated stink bug (unsprayed)||7.5||2.0||4.0|
|Spotted tentiform leafminer||20.0||20.0||27.0|
|Lesser peachtree borer||52.0||48.0||25.0|
|San Jose scale||0.0||0.0||2.5|
*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
|Jun 14||Jun 21||Jun 28|
|Codling moth (Biofix: April 10)
|Oriental fruit moth (Biofix: March 27)
|Tufted apple bud moth (Biofix: April 30)
2021 Pest Trends (click to enlarge)
Visit WNC Orchard Insect Populations for archived posts.