From the Blueberry Bulletin
Dr. Cesar Rodriguez-Saona, Extension Specialist in Blueberry Entomology
Mr. Dean Polk, IPM Agent – Fruit
Mr. Gene Rizio, IPM Program Associate – Fruit
- Cranberry Weevil
- Plum Curculio
- Rimon on PC
- Red Banded Leafrollers
Cranberry Weevil (CBW): Over the past 7 days 65% of beating tray samples have been positive for CBW. Of these, 21% have been at or above the threshold of 5 adults/bush. Most of the samples have been taken at wooded edges. On occasion samples may have been taken 50 or more feet into the interior. Several of these interior samples showed levels over the treatment threshold, especially where activity was excessive at the edges. Full field sprays may be needed in these cases for good results. As flower petals become fully visible CBW begins to retreat to other hosts and will no longer be a risk.
Plum Curculio (PC): The first PC adult was seen on a beating tray sample on 4/16 in Atlantic County. While they were seen earlier in experimental traps, this marks the first presence in the bushes. PC adults will be something to watch for from now through the first post pollination sprays, although no insecticides can be applied during bloom. If historically you have high populations of PC and would like to use Rimon, we recommend using Rimon between the end of this week and early next week, before you place bees in your fields.
Use of Rimon against PC
We have tested a preventive PC control using Rimon (novaluron) pre-bloom. Rimon is a chitin inhibitor. It affects larval development but also has transovarial activity. Thus, eggs can become sterile when adults ingest Rimon-treated plants. Rimon does not control adults; thus, you might still need a post-bloom application. Rimon needs to be ingested by adults. It needs to be applied right before bloom. Rimon does not have direct toxicity to adult bees but if it gets on pollen it can be carried to the hive and affect the brood. Based on our data, 25 oz/A of Rimon at 25 gal/A works best. Rimon applied to young foliage causes phytotoxicity. Based on our observations plants grow out of this but growers should be aware of these effects.
Redbanded Leafrollers (RBLR): Adults are starting to show up on traps at low levels.
