We track local insect populations throughout the growing season using a system of traps, temperature-recording devices, and degree-day models. Traps and weather data are checked weekly, with results updated by Tuesday afternoon from April through September. Learn more about southeastern apple pests at the Apple Pest Management page.
Based on the codling moth degree-day model, Henderson County is currently in the middle of second generation flight, while off the mountain in Polk County the second generation flight is complete. Pheromone trap captures in the few locations where significant populations exist agree with the model. In the vast majority of orchards codling moths are very low and one insecticide application against the second generation is probably sufficient. Under such low densities the timing of that application is not highly critical, and last week or this week is OK in Henderson County.
Oriental fruit moth pheromone trap captures continued a two-week trend of declining numbers. Lower numbers were likely due to the use of sprayable OFM pheromone in several of our monitoring orchards and insecticides applied for second generation codling moth.
Of particular significance was a relatively large jump in apple maggot captures on traps in our two abandoned orchards – they averaged 2 flies last week and 5 flies per trap this week. Orchards located near abandoned sites are obviously at greatest risk of infestation.
2014 Average Weekly Trap Captures*
|HENDERSON COUNTY||POLK COUNTY|
|Insects per trap||Insects per trap|
|Oriental Fruit Moth
|Tufted Apple Bud Moth||0.5||2.0||1.0||0.0||1.0||1.0|
|Brown Marmorated Stink Bug||0.3||0.0||1.0||-||-||-|
|Spotted Tentiform Leafminer||46.0||34.0||24.0||-||-||-|
|Lesser Peachtree Borer||18.0||3.5||3.5||-||-||-|
*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.
2014 Accumulated Degree Days
|Henderson County|| Polk County
|Codling Moth||Biofix 5/2||1325||1441||1593||Biofix 5/2
|Oriental Fruit Moth||Biofix 4/7||1973||2127||2310
|Tufted Apple Bud Moth||Biofix 4/28
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:
2014 Pest Trends (click to enlarge)
UPDATED July 28