Leafminers are present now as tissue feeding mines when they are easily visible from the upper leaf surface. Within a week, second generation moths should begin to emerge from the mines. I have only found one orchard with high numbers of leafminers this year, even though many growers did not apply any insecticides aimed at leafminers. It seems as though this insect is declining as a pest. I think for next year, no growers should apply a preventative spray against leafminers.
European red mites will be building during this hot weather. Mites are primarily
eggs right now, but adults and nymphs may be present as well. It is better
to control mites before mites cause bronzing damage. There are many miticides
to choose from. Look at the table on page 136 of your 2008 NE Tree Fruit Management
Guide. It is best not to use the same miticide two years in a row. Also, Kelthane
has not been very effective for most growers and I think it is too late in
the season to use AgriMek effectively. Other than those two, any of the miticides
should work well. Some growers have had trouble controlling mites, but I think
the reason for this is not applying enough water and therefore not getting
good coverage. When applying a miticide, spray as much water per acre as you
Green apple aphids should be building on the ends of branches soon. This is one pest you can generally ignore. Aphids almost always build up, then are consumed by aphid predators. If you see lots of aphids, wait a week. It usually only take one week for the aphids to be controlled by the predators.
I started finding apple scab on fruit this week. Check your leaves and fruit
for scab. If you find more than a little bit of scab, apply a full rate of
Captan and repeat in 7 days.
Next Thursday, June 19, is our third and final twilight meeting. It’s at Sweet Berry Farm in Middletown. Sweet Berry Farm is an amazing farm! The meeting starts at 5:30 and costs $20 per learning individual.
With plum curculio finished and hopefully no apple scab in your orchard, it's a great time to lengthen the time between pesticide applications. If you have no apple scab, your trees probably don't need to be sprayed for 2-3 weeks!
Thank you for calling. Next week the message will be recorded on Wednesday, June 18.