Finding a tiny white, worm-like larva inside a raspberry, blackberry, blueberry, strawberry, or similar fruit can be unpleasant, but it is not necessarily a sign that the berries are dangerous. One common culprit is the spotted-wing drosophila, a small fruit fly whose larvae develop inside ripening soft fruit. The larvae can be difficult to notice until the berry is opened, and infestation may sometimes become apparent only after the fruit has been harvested.

Spotted-wing drosophila larvae are considered harmless to humans when accidentally consumed. University of Minnesota Extension states that there is no known human-health risk from eating fruit containing these larvae. However, infested berries can become soft, damaged, fermented, or more vulnerable to other insects, fungi, and bacteria, so the condition of the fruit still matters.

If you discover larvae in your berries, don’t panic—but inspect the fruit carefully. Discard berries that are rotten, moldy, badly damaged, or have an unpleasant fermented or sour smell. Berries that otherwise look sound can be refrigerated, which slows the development of the larvae. Before eating fresh produce, the FDA recommends washing it thoroughly under clean running water; soap, detergent, or commercial produce washes are not recommended.

So, yes, tiny white larvae in fresh berries are a real phenomenon, and they are often associated with fruit flies such as spotted-wing drosophila. Their presence can certainly be alarming, but it does not automatically mean the fruit is poisonous or unsafe. The more important concern is whether the berries are spoiled or contaminated with harmful microorganisms, which is why proper washing, refrigeration, and common-sense inspection remain important