Arthropod Situation

European Apple Sawfly and Tarnished Plant Bug:  Trap captures for these two pests were fairly low at the UVM HRC this season, and no major infestations were reported by commercial growers. Given the below-threshold captures before bloom, we did not apply a pre-bloom insecticide for the first time ever this year.  Fruit damage from EAS and TPB has been low.

European Red Mites:  Given the cool, wet weather we experienced this spring, oil application was difficult to time.  It seemed that whenever there was a window of weather without wind or rain, cold temperatures were predicted.  The  growing season continued to be cool and wet, which are conditions that do not favor mite build-up.  At the UVM HRC, we were again fortunate  -- this was our second year in a row that we did not have to apply a miticide after the early season oil application.

Leafminers:    In most of the orchards visited around the state, first generation mines were below threshold.   At the UVM HRC, while early captures of LM on red trunk traps did not exceed threshold, we did eventually see a higher infestation as the season progressed.  The worst area for leafminer damage at the UVM HRC occurred in a small low-spray block where we had placed ten pheromone traps to see if increasing the number of traps could reduce the level of LM damage.  In other words, whereas our other monitored blocks each contained a single baited wing trap for monitoring second-generation and later flights, the small (1.1 acre) low-spray block had ten traps.  During our weekly standard monitoring for mines, this block had higher levels of foliar damage.  Currently,  a number of our blocks have very high numbers of 3rd generation mines (some leaves have as high as 8 new mines per leaf).  Hopefully, the rest of the state does not have such a high overwintering population.

Plum Curculio:  Plum curculio pressure was light this year as it also was in 1999.  The cool temperatures in the first half of June extended the potential "activity period" but even when it warmed up towards the end of June, there was not an apparent flush of PC activity, at least on non-sprayed trees at the UVM HRC.   

Mullein Bug:  Mullein bug damage was observed on Delicious fruit in a few Vermont orchards

Potato Leafhopper:  It seemed PL were more of a problem this year in Vermont compared to recent years.   At the UVM HRC, we had somewhat extensive damage on a young planting. 

Apple Maggot:  At the UVM HRC, AMF captures on baited red spheres were fairly low this year, but the action threshold of an average of  five adults per sphere was reached during the second week of August.  Certain hot spots in the orchard adjacent to unsprayed crabapples helped to bring this average up.  Late-season populations remained high, especially in the hot spots.