Within the past 3-4 years California has experienced an invasion of the Spotted Wing Drosophila fruit fly. It is affecting cherries and other soft bodied fruits such as berries in a significant way. Numerous gardeners have complained about finding the little white worms inside cherries just at harvest time.
These worms are the larvae of a fruit fly that has been a pest in Japan for decades, but somehow made it to the US. It has no known enemies in the US, so it has spread, unchecked, like wild fire. Though the main concern is cherries, this pest has also turned up in raspberries, strawberries and blueberries.
The University of California at Davis has guidelines for dealing with the pest so home owners can preserve their harvests. For detailed look at the problem check out the
UC web site: http://www.ipm.ucdavis.edu/EXOTIC/drosophila.html.
or check out a more detailed,up-to date flier here, http://www.ipm.ucdavis.edu/PDF/MISC/2014_Cherry_Spotted_Wing_Drosophila.pdf.
The first link goes to a page written for home owners, and the second link goes to a more up-to-date flier written for farmers, so some of the terminology is more scientific.
Summarizing the approach suggested is as follows:
Good control can be achieved with a few well timed pesticide sprayings beginning when the earliest maturing variety in the orchard is just starting to turn from green to straw-colored.
Spray trees using Spinosad or Pyrethrin, both are organic. (Spinosad is available as Monterey Lawn & Garden Spinosad, or Captain Jacks Dead Bug Brew.) (Pyrethrin is available as Monterey Take Down.)
Traps should be set to determine if the fruit flies are present. Directions for making traps are included in links below.
In the case of spraying, it has been said that no treatment is effective unless the entire tree can be sprayed. Spinosad, and Take Down should be alternated week to week, one spray of spinosad, one spray of Take Down. This helps prevent the fruit flies from developing resistance to the sprays.
Both these products have been shown to remain effective on the plant for 7-14 days, so it is suggested that sprays be applied accordingly.
These worms are the larvae of a fruit fly that has been a pest in Japan for decades, but somehow made it to the US. It has no known enemies in the US, so it has spread, unchecked, like wild fire. Though the main concern is cherries, this pest has also turned up in raspberries, strawberries and blueberries.
The University of California at Davis has guidelines for dealing with the pest so home owners can preserve their harvests. For detailed look at the problem check out the
UC web site: http://www.ipm.ucdavis.edu/EXOTIC/drosophila.html.
or check out a more detailed,up-to date flier here, http://www.ipm.ucdavis.edu/PDF/MISC/2014_Cherry_Spotted_Wing_Drosophila.pdf.
The first link goes to a page written for home owners, and the second link goes to a more up-to-date flier written for farmers, so some of the terminology is more scientific.
Summarizing the approach suggested is as follows:
Good control can be achieved with a few well timed pesticide sprayings beginning when the earliest maturing variety in the orchard is just starting to turn from green to straw-colored.
Spray trees using Spinosad or Pyrethrin, both are organic. (Spinosad is available as Monterey Lawn & Garden Spinosad, or Captain Jacks Dead Bug Brew.) (Pyrethrin is available as Monterey Take Down.)
Traps should be set to determine if the fruit flies are present. Directions for making traps are included in links below.
In the case of spraying, it has been said that no treatment is effective unless the entire tree can be sprayed. Spinosad, and Take Down should be alternated week to week, one spray of spinosad, one spray of Take Down. This helps prevent the fruit flies from developing resistance to the sprays.
Both these products have been shown to remain effective on the plant for 7-14 days, so it is suggested that sprays be applied accordingly.
Oregon State Extension has a nice collection of vide0s to help wth the control of Spotted Wing Drosophila Fly.
Prevent Worms in Cherries