Well, plum curculio finally got active over the weekend. Saturday’s warm, humid conditions were ideal for plum curculio, and the curcs took advantage of the opportunity. I found damage primarily on unsprayed trees next to woods. There is still time for more plum curculio damage, so if your trees do not have sufficient insecticide protection now, spray them right after the rain on Wednesday. According to Orchard Radar (https://www.uri.edu/research/ipm/), plum curculio should stop migrating into orchards around June 9 in Providence County and June 13 in Newport County. That means your fruit should be protected with an insecticide through those dates. So trees sprayed with an insecticides since May 27 in Providence County and since May 31 in Newport County, should be protected until the end of plum curculio season. This is providing we get less than 1 inch of rain on Wednesday, June 4. If we get more than one inch of rain, I’m afraid too much insecticide will be removed and trees could suffer more plum curculio damage. So, if we get a lot of rain on Wednesday, I suggest you apply another insecticide before the weekend. Hot and humid weather is predicted for this weekend. Plum curculio could do a lot of damage if fruit are not protected with an insecticide this weekend.

Leafminer. I did find one orchard today with high levels of leafminer. Leafminer mines are easy to see now from the upper leaf surface. The white poke-a-dotted mines are primarily on fruit cluster leaves. Threshold for leafminers are not exact. Let’s say if you find 1 mine for every 2 clusters, consider applying Provado or Calypso when the next generation mines are small, probably at the end of June or early July. Here’s an old leafminer factsheet, but there are good pictures. Click on the “tent-like appearance” in the Larvae section of the factsheet to see what the tissue feeding mines look like. http://www.nysipm.cornell.edu/factsheets/treefruit/pests/stlm/stlm.asp

Last week I said unsprayed European apple sawfly should be moving into second fruits soon; well I started seeing them in second fruits on May 30. Unsprayed (or attempts at organic control) European apple sawfly damage can get pretty messy looking with lots of reddish-brown frass, but an insecticide spray should stop them advancing into additional fruits. Here’s a Cornell factsheet: http://www.nysipm.cornell.edu/factsheets/treefruit/pests/eas/eas.asp

Continue to check your trees for developing apple scab lesions. If you find lesions, apply full rates of Captan or Captec 7-10 days apart. The hot, dry weather forecasted plus Captan is probably the best way to attack active scab lesions.

Next message on Tuesday, June 10th (949-1456)