The main items right now are timing of fruitworm sprays and fungicides. The fruit set seems to be coming along slowly. We are just doing our first fruitworm on a piece of Stevens this weekend. Some growers have already done their 2 shots, so it’s very variable out there. Altacor is the best choice. Remember, fungicides can do their best work when applied to FLOWERS...
Cranberry IPM Message
We have been hearing of reports of uprights exhibiting classic symptoms of frost damage, known as umbrella bloom. In addition to frost injury, umbrella bloom is also associated with insufficient chilling hours; there are also reports of this type of damage from mites or insects, but we have not seen this much in MA.
If you are using pheromone traps for timing management of girdler, black-headed fireworm and/or Sparganothis, you should be monitoring and counting moths at least weekly; more visits may be needed if counts are high. Baits should be changed every 3 weeks.
Pheromone traps to monitor for Spag, BHF, and/or cranberry girdler, should be up.
Timing for Diazinon (or Sevin) treatment is here (or coming up) for Vaccinium scale. Check your bogs. There is a lot of variation among beds. All scale samples that were checked this week showed that egg production has started. For super hybrid samples, crawlers were emerging, and we advised sprays for this weekend and next week.
We have dissecting microscopes available in our Diagnostic Lab (Rm 121) and in our Entomology lab (Rm 106) that you can use to examine your sweep net contents or upright samples. Just come on down, the labs are available 8:30-4:30. If one of us is around, we are glad to help or you can do the inspection yourself, whatever works best.
This has been a difficult spring for getting sprays out due to all the frost nights.
This past week proved to be a challenging time to sweep! Despite fairly high winds and cold temperatures, cranberry weevils have been picked up. Populations of weevil are expected to continue to grow as more weevils move out of the woods and off blueberry and onto cranberry. Your insecticide choices for management are Avaunt, Actara and Fanfare. Remember Fanfare has a 100-day or...
Sweeping this past week has yielded high numbers of cranberry weevil and green spanworm, sometimes in numbers over threshold. Various colors of (springtails) colembolas (red, yellow, and black) have also been picked up. BHF larvae are likely out there, but they are very hard to see.
With all the cool temperatures we have had this spring, most growers are planning to start sweeping next week (week of May 8). Sweeping this week only resulted in a very few weevil and many collembola/springtails (not a cranberry pest, but very abundant on bogs in many colors) – see attached pic. Coming next week, tiny blackheaded fireworm larvae of the most concern...
