Spotted Wing Drosophila
Spotted Wing Drosophila (SWD) (Drosophila suzukii) is a new fruit pest recently discovered in Davis County, Utah (August, 2010).
SWD is similar to other vinegar flies (genus Drosophila), except they can infest unripe fruit. SWD can be easily controlled using insecticides common in fruit integrated pest management plans. If SWD is caught in monitoring traps, insecticide applications must be used during the unripe fruit stage to prevent damage.
Adults are 2 to 3 mm long, with red eyes, pale brown bodies, and feather-like antennae. Males have one circular black spot per wing, and females have no spots on wings.
- Eggs are small, white, and inserted into fruit.
- Larva are small cream-colored maggots with black mouthparts.
- Pupa are small brown, cylindrical capsules with two extensions on one end.
- Sunken fruit
- Holes in fruit
Control is not recommended unless SWD is caught in monitoring traps, fruit injury is detected, or a high-value crop needs protecting.
A SWD control program starts with monitoring. If SWD is detected, chemical control is necessary to preserve the marketability of fruit. For commercial growers, some chemicals already used in your IPM program for similar pests should give effective control of SWD. To protect fruit, an additional insecticide application will be needed at the pre-ripe (straw color) stage, with additional applications as per the label directions through harvest, and post-harvest if a high volume of fruit remains on trees or plants.
Cultural and Mechanical Controls:
- Use traps throughout and around fruit production areas to capture and kill adult flies.
- Damaged or fallen fruit should be removed from the property, buried, solarized, or stored in a sealed container to exclude flies. Remove neglected fruit orchards.
- Fine-mesh floating row covers can protect low growing fruits.
- Pick ripe fruits frequently to minimize potential SWD host material where populations may build
- Infested harvested fruit may be stored at 35°F or lower for at least 96 hours to kill developing eggs, larvae, pupae, and adults.
Identifying/Trapping Spotted Wing Drosophilas