1. Identification of larvae in strawberries
The tiny white worms occasionally seen wriggling out of strawberries after soaking in salt water are larvae of the Spotted Wing Drosophila (SWD), a fruit fly species. These larvae measure about 1 to 3 millimeters long and are pale and translucent, making them difficult to notice without deliberate inspection.
They develop inside the soft flesh of ripening strawberries, feeding from within after the eggs hatch. The eggs are deposited just beneath the skin by adult female flies, and the larvae grow rapidly, especially in warm, humid environments, leading to infestations in affected berries.
2. Spotted Wing Drosophila overview
Spotted Wing Drosophila (Drosophila suzukii) is a small fruit fly originally from Southeast Asia that has spread to many fruit-growing areas worldwide. Unlike typical fruit flies that infest overripe or damaged fruit, SWD targets healthy, ripening fruits such as strawberries, blueberries, and cherries.
Adult SWD measure 2 to 3 millimeters and have distinctive red eyes and a yellowish-brown body. Males feature dark spots on their wings, which is the source of their name. Females possess a serrated ovipositor that allows them to cut into the skin of ripening fruit to lay eggs, making them particularly problematic for growers.
