WNC Orchard Insect Populations for August 14, 2018
Overall insect pressure remains low in most areas. While degree-day accumulations coincide with early egg hatch of the third generation in lower elevation orchards (e.g., Cleveland, Lincoln Counties), this generation should not require control unless damage from previous generations is evident, which seems to be rare. In higher elevations (e.g., Henderson County), DD accumulations coincide with the tail end of second generation egg hatch, and pheromone trap captures remain low. OFM pheromone traps captures are also very low throughout the area.
Based on pheromone trap captures in multiple apple orchards, first-generation adult brown marmorated stink bug emergence continues in the mountains, and has slowed down considerably in lower elevation orchards (less than 1000 ft elevation). Populations to date do not appear to be especially high, so two-week interval applications should be sufficient in those locations where protection is of greatest need – i.e., fresh market production.
We continue to capture apple maggot flies on traps in abandoned orchards, which is to be expected this time of the year. However, dispersal from these sites usually declines considerably later in the season, so further insecticide application specifically targeting this insect are probably not needed moving into next week, with the exception being those orchards near abandoned sites.
Learn more about southeastern apple insect pests at the Apple Insect Management page.
2018 Average Weekly Trap Captures*
|Insects per trap|
|Oriental Fruit Moth||17.7||13.0||17.0|
|Tufted Apple Bud Moth||3.0||1.0||0.0|
|Apple Maggot (abandoned and research)||19.3||21.3||14.3|
|Brown Marmorated Stink Bug (commercial – mountains)||0.8||1.0||1.3|
|Brown Marmorated Stink Bug (commercial – upper piedmont)||2.2||1.8||1.1|
|Brown Marmorated Stink Bug (research – unsprayed)||1.8||1.3||5.2|
|Spotted Tentiform Leafminer||5.0||3.0||0.0|
|Lesser Peachtree Borer||10.5||10.5||3.0|
|San Jose Scale||2.5||5.0||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||1950||2100||2295|
|Oriental Fruit Moth||Apr 2||2633||2819||3054|
|Tufted Apple Bud Moth||May 4||2314||2500||2735|
|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: