Spotted Wing Drosophila Alert

Dear Blueberry Growers,

Many of you have started harvesting. The spotted wing drosophila has been found strawberry and raspberry fields in southern Maine so far, especially in the vicinity of Warren, where one trap in a strawberry field contained 98 SWD flies.

We are trapping 30 blueberry fields and found 1 SWD fly in a trap in a Franklin blueberry field, in the forest edge.

So, please be vigilant and keep trapping for this potentially devastating pest. I will provide an update when we trap more flies.

Frank Drummond

Time to put out your mummy berry plots for next year

This is a good time to collect mummy berries from your plants to put out in mummy berry plots for next year. The mummy berries are easy to see before harvest since they are grey and shriveled compared to the plump ripening blueberries.   The clones vary in the number of mummy berries they produce so you may need to look at a few places in your field for enough mummy berries for your plots.  You will need about 50 mummy berries (up to a 100) per plot.  Please see below for instructions on how to put mummy berry plots.

We are looking for growers who are willing to check their mummy berry plots twice a week and report to me on the development of the mummy berry cups.  We want to place our weather stations in fields with monitored mummy berry plots next year.   Please let me know if you would be willing to put out a mummy berry plot and have a weather station in your field.

If you are willing to have a weather stations and monitor plots, but do not have the experience or time to put out mummy berry plots, we can come to your field and collect mummy berries and set up the plots for you.

Please contact Seanna Annis at 207-581-2621 or via email at sannis@maine.edu if you are willing to be a monitor of mummy berry next year OR have any questions.

How to put out Mummy berry plots

1. Collect about 150 mummy berries (50 for each mummy berry plot) from your crop field(s) near  harvest (or from the process line or winnow piles if you have them). The mummy berries will be whitish grey and smaller than the berries and will have dropped onto the surface of the leaf litter, or may still be in amongst clusters of healthy berries on stems.  Often clones produce different amount of mummy berries, so if there are no mummy berries in one spot, try another area in your field.  Often there are more mummy berries at the edges of fields. 

 2. In next year’s crop field, choose 3 areas within your blueberry field. I suggest 3 areas because each year at least one of our plots has not worked in a field.  Each area should be about 3” by 3” that is clear of stems but amongst the plants.  Choose areas that look like they have damp soil most of the time AND will be easy for you to access next spring. These areas do not need to be widely spread around the field, 5 to 10 ft between each one will be fine.  If you have different exposures, soil types or large shaded areas in your field you may want to place your mummy berry plots around your field to get the full range of when the mummy berries develop. The areas should not be on slopes where the mummy berries will be washed away, in hollows where they will be water-logged or in areas with lots of frost-heaves.  

3. In each 3" by 3" area, clear off the leaf litter to one side and scrape off about ¼” of hard packed soil and put aside.   Place about 50 mummy berries on the surface of the soil and press the mummy berries firmly into the soil (with your fingers or step on them).   The mummy berries need to be buried in soil but not more than ½” deep at most.  Cover the mummy berries with a small amount of dirt (1/4”) on top and press them firmly down again.  You should NOT be able to see the mummy berries.  Replace the leaf litter over the mummy berries to provide protection over the winter.

4. VERY IMPORTANT: STAKE or flag the plots on either side so you can locate them in the spring.  Two stakes or flags makes it much easier to figure out where to look in the spring.

Questions: Contact Seanna Annis at 207-581-2621 or sannis@maine.edu