WNC Orchard Insect Populations for September 11, 2018
September 11, 2018
As mid-September approaches, populations of most insect pests are on the decline. Codling moth, oriental fruit moth, and apple maggot are no longer of concern in >99% of orchards. While brown marmorated stink bug adults are still active, they too will soon begin to decline as they disperse to overwintering sites in the next 7 to 10 days. Overall, BMSB damage has been quite low, and averages less than 2% across more than 20 orchards sampled during the past week. The fact that overall damage did not appreciably increase since the last damage estimates in mid-August suggests that within-orchard populations are very low and the potential for further damage is also low. The expected rains associated with Hurricane Florence will further suppress BMSB activity.
Unless something unusual in the insect world occurs in the next couple of weeks, this will be the last Insect Update for 2018.
HOWEVER, if anyone comes across large numbers of BMSB adults congregating on homes, sheds, or vehicles in the coming weeks, or if you hear about large numbers of bugs occurring somewhere else, please get in contact with either Jim (828-684-3562) or Steve (828-713-4000). By large numbers, we’re talking about hundreds to thousands. We’re always looking for good collection sites, and willing to travel on short notice to collect.
Learn more about southeastern apple insect pests at the Apple Insect Management page.
2018 Average Weekly Trap Captures*
|Insects per trap|
|Oriental Fruit Moth||29.0||40.0||15.0|
|Tufted Apple Bud Moth||0.0||0.0||0.0|
|Apple Maggot (abandoned and research)||4.0||1.0||0.5|
|Brown Marmorated Stink Bug (commercial – mountains)||2.2||4.2||2.2|
|Brown Marmorated Stink Bug (commercial – upper piedmont)||3.3||5.9||4.7|
|Brown Marmorated Stink Bug (research – unsprayed)||8.4||14.0||14.5|
|Spotted Tentiform Leafminer||0.0||0.0||0.0|
|Lesser Peachtree Borer||37.0||57.5||8.5|
|San Jose Scale||212.5||540.0||212.5|
*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||2595||2844||2942|
|Oriental Fruit Moth||Apr 2||3424||3723||3841|
|Tufted Apple Bud Moth||May 4||3105||3404||3522|
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: