Strawberry fruit flies - Ask Extension
I looked at the "Strawberries for the Home Garden" Ver 7.0 because I am having serious fruit fly issues with my berries. I noticed that fruit flies...
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Strawberry fruit flies #151536
Asked September 07, 2013, 3:23 PM EDT
I looked at the "Strawberries for the Home Garden" Ver 7.0 because I am having serious fruit fly issues with my berries. I noticed that fruit flies are not addressed in this CSU story, yet I have more aggressive fruit flies than described in other state agriculture or extension reports in CA, KS, or IL.
I have tried some pesticide spray (not malathion) that did nothing, a recommended dishsoap and water spray, equally ineffective. I have now tried bowls of yeast and sugar with a plastic wrap cover that does seem to trap a good number of fruit flies. However, all the discussion seems to indicate that the flies are only a problem with ripe or over-ripe fruit. These flies are infecting berries that haven't even begun to ripen, some with barely a tinge of pink, and by the time they are even solid pink the larvae are eating through them and turning the berries soft.
The fruit flies have red eyes, and I have attached a picture of the larvae (center of pic with seeds shown for size comparison). Another person I know has the same problem.
I live in Arvada, it's a raised bed, and I think the third or fourth year for these plants. The fruit is prolific, just wish I could eat it!
Lyman
I have tried some pesticide spray (not malathion) that did nothing, a recommended dishsoap and water spray, equally ineffective. I have now tried bowls of yeast and sugar with a plastic wrap cover that does seem to trap a good number of fruit flies. However, all the discussion seems to indicate that the flies are only a problem with ripe or over-ripe fruit. These flies are infecting berries that haven't even begun to ripen, some with barely a tinge of pink, and by the time they are even solid pink the larvae are eating through them and turning the berries soft.
The fruit flies have red eyes, and I have attached a picture of the larvae (center of pic with seeds shown for size comparison). Another person I know has the same problem.
I live in Arvada, it's a raised bed, and I think the third or fourth year for these plants. The fruit is prolific, just wish I could eat it!
Lyman
Jefferson County Colorado
Expert Response
I believe you have the spotted wing drosophila.
It is moving into Colorado and has been reported in a few counties here. Below is some information on the pest from our Extension Entomologist,Whitney Cranshaw.
The spottedwing drosophila (Drosophila suzukii) is an insect of Asian origin that was first discovered in North America in 2008. This insect has caused considerable concern because it is capable of damaging intact ripe fruit, particularly soft-fleshed fruit such as raspberries, strawberries and grapes. The injury from this insect that is most likely to be observed is the presence of numerous, tiny pale-colored maggots in the flesh of ripe berries. If reared to adulthood, males of this species are identifiable by having a dark spot on the forewing. The first Colorado record of this insect was from Fort Collins in 2012. It is important that surveys be done during the upcoming season to identify other areas where this important pest may have become established. If you think you have found this insect in Colorado please report it so that the establishment and spread of the spottedwing drosophila in Colorado can be tracked. Suspected samples of spottedwing drosophila can be submitted to County Extension offices or directly to the CSU campus. If using the latter please send the samples to Department of Bioagricultural Sciences and Pest Management, Attn: Whitney Cranshaw, Colorado State University, Fort Collins, CO 80523-1177. Prior to sending samples, email contact is suggested (<personal data hidden>) Note: There are numerous other Drosophila species found in Colorado. These develop on the yeasts of overripe fruit and are the well known "fruit flies" of the fruit bowl. Although very similar in appearance, these do not attack intact fruit. Adults of these other Drosophila species also lack any wing spotting.
It is moving into Colorado and has been reported in a few counties here. Below is some information on the pest from our Extension Entomologist,Whitney Cranshaw.
The spottedwing drosophila (Drosophila suzukii) is an insect of Asian origin that was first discovered in North America in 2008. This insect has caused considerable concern because it is capable of damaging intact ripe fruit, particularly soft-fleshed fruit such as raspberries, strawberries and grapes. The injury from this insect that is most likely to be observed is the presence of numerous, tiny pale-colored maggots in the flesh of ripe berries. If reared to adulthood, males of this species are identifiable by having a dark spot on the forewing. The first Colorado record of this insect was from Fort Collins in 2012. It is important that surveys be done during the upcoming season to identify other areas where this important pest may have become established. If you think you have found this insect in Colorado please report it so that the establishment and spread of the spottedwing drosophila in Colorado can be tracked. Suspected samples of spottedwing drosophila can be submitted to County Extension offices or directly to the CSU campus. If using the latter please send the samples to Department of Bioagricultural Sciences and Pest Management, Attn: Whitney Cranshaw, Colorado State University, Fort Collins, CO 80523-1177. Prior to sending samples, email contact is suggested (<personal data hidden>) Note: There are numerous other Drosophila species found in Colorado. These develop on the yeasts of overripe fruit and are the well known "fruit flies" of the fruit bowl. Although very similar in appearance, these do not attack intact fruit. Adults of these other Drosophila species also lack any wing spotting.
Thank you. I sent an email to Whitney along with some new pictures.
Here's one of some of the drosophilia in the yeast trap I made, which shows them pretty clearly in the magnified water droplets.
Here's one of some of the drosophilia in the yeast trap I made, which shows them pretty clearly in the magnified water droplets.
Thanks for the great pictures!
