Farm Journal- August
Attention Farm Patrons:
The Spotted Wing Drosophilia (Drosophila suzukii)
aka The Asian Fruit Fly
This invasive fruit fly, native to Asia, first surfaced in California in 2008 and has made its way across the country since, arriving in New England in 2011. Specimens were found for the first time on our farm the week of July 23rd in one of the traps placed, at our request, in the field early this summer by the Barnstable County Extension Service.
The Asian Fruit Fly, unlike the fruit flies that we are familiar with, attacks the fruit from first color until it is ready for harvest. The flies multiply rapidly and could devastate a crop of untreated blueberries. Other small fruits are also at risk, tree fruits such as peaches and apples, and even some vegetables, like tomatoes. Fruit farmers all over the country are struggling with this insect; Maine blueberry growers are especially anxious.
Because there is no known method of control, without using insecticides, there is no alternative but to use them, something I have been able to avoid thus far at the farm- spray the fruit near harvest. We did so on July 25 with the same chemical that I use against Winter Moth very early in the season. It is called Delegate, an extract from a soil bacteria that is relatively less toxic than other choices. EPA requires a 3 day waiting period between spraying and harvest for this insecticide. Although it is then okay to eat the berries, it would be wise to only eat a small quantity (or none at all) of unwashed berries in the field right from the bush, which unfortunately reduces the “fun factor”. I may have to spray again before the end of the season and may have to use a different insecticide to protect the fruit.
We offer the following picking advice to minimize the chance of getting bad berries now that the insect is present. Ripe fruit is soft but there is a difference between good soft and bad soft. A slight squeeze between your fingers as you pick the berry will help you differentiate between them. Good ripe fruit will quickly spring back against your fingers, while bad fruit will do so slowly or not at all. There are obvious visual signs of bad fruit whether from the fly or disease. Look for broken skin, discoloration, a flat spot, a shrunken appearance, or leaking fruit. For those who freeze the berries, they can still be frozen unwashed, but if you want to wash before freezing, we recommend drying them on paper towels first (a hair dryer will speed up the process). All this requires more attention during picking in addition to sorting your fruit after harvest. Please note that this fly is not harmful to human health only to the berries, however, there is an obvious “ick” factor involved.
We ask for your patience as we begin to tackle this very challenging problem. We understand if there may be concern on your part about the quality of the berries. As far as we know from our summer long tests, the fly has arrived only recently and the population is presently very small. This is also confirmed by the fact that many people have noticed and remarked on the exceptional beauty and sweetness of the berries this summer, infected berries would show extensive damage. So, to the best of our knowledge it is safe to assume the berries you have picked so far were fine.
The Spotted Wing Drosophilia (Drosophila suzukii)
aka The Asian Fruit Fly
This invasive fruit fly, native to Asia, first surfaced in California in 2008 and has made its way across the country since, arriving in New England in 2011. Specimens were found for the first time on our farm the week of July 23rd in one of the traps placed, at our request, in the field early this summer by the Barnstable County Extension Service.
The Asian Fruit Fly, unlike the fruit flies that we are familiar with, attacks the fruit from first color until it is ready for harvest. The flies multiply rapidly and could devastate a crop of untreated blueberries. Other small fruits are also at risk, tree fruits such as peaches and apples, and even some vegetables, like tomatoes. Fruit farmers all over the country are struggling with this insect; Maine blueberry growers are especially anxious.
Because there is no known method of control, without using insecticides, there is no alternative but to use them, something I have been able to avoid thus far at the farm- spray the fruit near harvest. We did so on July 25 with the same chemical that I use against Winter Moth very early in the season. It is called Delegate, an extract from a soil bacteria that is relatively less toxic than other choices. EPA requires a 3 day waiting period between spraying and harvest for this insecticide. Although it is then okay to eat the berries, it would be wise to only eat a small quantity (or none at all) of unwashed berries in the field right from the bush, which unfortunately reduces the “fun factor”. I may have to spray again before the end of the season and may have to use a different insecticide to protect the fruit.
We offer the following picking advice to minimize the chance of getting bad berries now that the insect is present. Ripe fruit is soft but there is a difference between good soft and bad soft. A slight squeeze between your fingers as you pick the berry will help you differentiate between them. Good ripe fruit will quickly spring back against your fingers, while bad fruit will do so slowly or not at all. There are obvious visual signs of bad fruit whether from the fly or disease. Look for broken skin, discoloration, a flat spot, a shrunken appearance, or leaking fruit. For those who freeze the berries, they can still be frozen unwashed, but if you want to wash before freezing, we recommend drying them on paper towels first (a hair dryer will speed up the process). All this requires more attention during picking in addition to sorting your fruit after harvest. Please note that this fly is not harmful to human health only to the berries, however, there is an obvious “ick” factor involved.
We ask for your patience as we begin to tackle this very challenging problem. We understand if there may be concern on your part about the quality of the berries. As far as we know from our summer long tests, the fly has arrived only recently and the population is presently very small. This is also confirmed by the fact that many people have noticed and remarked on the exceptional beauty and sweetness of the berries this summer, infected berries would show extensive damage. So, to the best of our knowledge it is safe to assume the berries you have picked so far were fine.
