Just a short message this week. Bloom is coming on strong this past week. It is absolutely the time to be putting out first fungicide. The weather has not been cooperative, so if you haven't yet sprayed, do it as soon as you have a chance. The window for controlling early season insects is closing unless you have really high numbers. We have had reports of 14 spag larvae and 20 weevils.
Cranberry IPM Message
This is the week of spag. There is, however, no easy answer!
Many growers have been treating with Avaunt over the past few weeks for winter moth or weevil. We learned that gypsy moth sometimes gets through Avaunt, similar to spag getting through. One site had false army, blossom, weevil, bhf on a few pieces plus some spag too with all at, or close to, threshold.
Insect populations continue to be low. However, now is the time to sweep!
Winter moth larvae are easily seen in sweep nets at this time. Populations are not nearly as high as expected this year, but it would be wise to check your own bog. Small gypsy moth, false army worm and even black-headed fireworm have been reported on bogs.
Winter moth larvae were picked up in sweeps last week. There is only a small window of opportunity to get out and sweep this week before the poor weather conditions come in, so try to get out there to see if winter moth is on your bog. Growers were picking up averages of 8-10 larvae last week. They are very small but you should be able to see them.
Some growers are reporting heavy infestations regarding fruit inspection and CFW pressure. Talking with the Ent lab, that concurs with what they are finding. "Most bogs have nothing but 1 in 10 will have a big (heavy) infestation similar to your numbers.
Cranberry fruitworm egg-laying is likely on the decline in most areas; first and second sprays have already gone out on most bogs. Reports on Spag flight indicate it is declining as well. Treatments with compounds other than Confirm or Intrepid (e.g.
Just some reminders from the Ent lab on using Altacor since it is a good choice for first fruitworm sprays. It works by causing paralysis of the insect by sustained contraction of the muscles. It has low toxicity to beneficials, especially pollinators. Please note: It will not function as a rescue spray against large larvae. It is most effective against small larvae.
Second generation black-headed fireworm is active during bloom. The timing for BHF is 2 weeks after the ONSET of flight if using growth regulators like Confirm or Intrepid (and again 10 days later). For other insecticides, including Delegate and Avaunt, apply 10 days after peak flight, which is usually during bloom.
Altacor is a new bee-safe insecticide for Sparganothis fruitworm, fireworm and cranberry fruitworm. Target EGGS as they are hatching and SMALL larvae, not larger larvae. Short rinse times (<6 min) are necessary for good coverage. It is expensive ($50/acre), but is longer lasting than some other compounds. 2 apps at 4.5 oz are allowed. Restricted use after July 15 by some handlers.