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 degree-day model, second generation egg laying is about 15% complete in Henderson County, but populations have generally been low throughout the region. Off the mountain in Polk County, the model predicts that egg laying of the second generation is about 65% complete, but densities have been also been very low in Polk. Under low-density populations, a single application targeting the second generation should be sufficient, and the window of opportunity for making that application is generally wide – generally from about 1500-1800 DD. However, in those orchards with damage or where pheromone trap captures have been greater than 5 to 7 per week, at least two applications are likely necessary.
Oriental fruit moth populations remain high in some, but not all locations. Numbers continue to remain very low in orchards using mating disruption, including sprayable OFM pheromone.
Apple maggot trap captures increased abruptly in one abandoned orchard, but remained low in another. In the absence of monitoring for this insect, it would be wise to assume a potentially damaging population exists.
2014 Average Weekly Trap Captures*
|HENDERSON COUNTY||POLK COUNTY|
|Insects per trap||Insects per trap|
|Oriental Fruit Moth
|Tufted Apple Bud Moth||3.0||0.5||2.0||0.0||0.0||1.0|
|Brown Marmorated Stink Bug||0.0||0.3||0.0||-||-||-|
|Spotted Tentiform Leafminer||88.0||46.0||34.0||-||-||-|
|Lesser Peachtree Borer||22.0||18.0||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||1172||1325||1441||Biofix 5/2
|Oriental Fruit Moth||Biofix 4/7||1785||1973||2127
|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 21