“Cherry bug” is a catch-all term for several insects that infest cherry trees and their fruit. The most common culprits are cherry fruit flies (whose larvae are the white maggots you find inside cherries), black cherry aphids, cherry slug sawflies, and spotted wing drosophila. Each one attacks a different part of the tree, causes different damage, and shows up at a different time of year.
Cherry Fruit Fly: The Maggot Inside Your Cherry
If you bit into a cherry and found a small white worm, you almost certainly met a cherry fruit fly larva. This is the pest most people mean when they search for “cherry bug.” The adult is a small fly with distinctive dark bands on its wings. It lays eggs just under the skin of ripening fruit, right around the time cherries start turning from green to a salmon-pink blush. Each female can deposit 50 to 200 eggs over about three weeks, with peak egg-laying happening when temperatures sit between 75 and 85°F.
Eggs hatch in five to eight days. The larva, a creamy white legless maggot that grows to about 5/16 inch long, burrows toward the pit of the cherry where it feeds for 10 to 21 days. At that point it chews its way out, drops to the ground, and burrows into the soil to pupate. Most emerge as adults the following spring, though some stay dormant for two years. The fly completes only one generation per year, with adults emerging around May and staying active until several weeks after harvest. Peak emergence often lines up exactly with harvest time.
Uncontrolled infestations can ruin nearly every cherry on a tree. Commercial markets have zero tolerance for cherry fruit fly larvae in packed fruit, which gives you a sense of how seriously growers take this pest. For backyard growers, yellow sticky traps hung in sunny parts of the tree canopy will catch adults and help you know when they’ve arrived. Check traps daily during the weeks before harvest.
Black Cherry Aphid: Curled Leaves and Sticky Fruit
Black cherry aphids are tiny, dark-colored insects that cluster on new growth at branch tips. They feed by sucking sap from the tree’s vascular tissue, and they’re found wherever cherries grow in the United States. On sweet cherry varieties, infested leaves curl severely and terminal growth gets disrupted. On tart cherries, the leaves don’t curl as dramatically, but the damage still adds up.
The real nuisance is honeydew, a sticky waste product the aphids excrete in large quantities. It coats leaves and fruit, and a black sooty mold quickly colonizes it. That mold stains fruit and makes it unmarketable for commercial growers. For home orchardists, it means ugly, sticky cherries. Heavy populations can stunt young trees, deform shoots, and even reduce fruit set the following year on mature trees. In severe cases, damaged leaves turn brown and die, and the fruit itself comes out undersized.
The good news: unless populations are extremely high, you can often ignore black cherry aphids on established backyard trees. Young trees with stunted growth or fruit covered in sooty mold are the situations that call for action.
Cherry Slug Sawfly: Skeleton Leaves
Despite the name, the cherry slug (also called pear slug or pear sawfly) isn’t a slug at all. It’s the larva of a small sawfly, and it earns its nickname from the olive-green slime covering its body. The young larva is tiny, wider at the front and slightly tapered at the back, and feeds on the upper surface of cherry and pear leaves. It scrapes away the top layer of leaf tissue, leaving behind translucent “windows” between the veins. This pattern is called skeletonizing.
A few larvae won’t cause serious harm, but heavy infestations turn leaves brown. They wither and drop, weakening the tree and potentially stunting fruit development. In its final growth stage the larva sheds its slimy coat, turns light orange-yellow, and reaches about 3/8 inch long before dropping to the soil. Because the larvae are soft-bodied and feed openly on leaf surfaces, they’re one of the easier cherry pests to manage.
Spotted Wing Drosophila: A Newer Threat
Spotted wing drosophila is an invasive fruit fly first detected in the U.S. around 2008 and now established across most cherry-growing regions. Unlike common fruit flies that target overripe or rotting fruit, this species attacks cherries as soon as they begin to soften and color. That distinction makes it far more destructive.
The fly reproduces in just 8 to 10 days, so populations can build rapidly during warm weather. Infestation risk climbs as fruit ripens and sits on the tree. Overripe cherries left unharvested are especially vulnerable. Detecting larvae requires cutting open or filtering fruit samples, since the damage isn’t always visible from the outside. For home growers, the simplest defense is harvesting promptly and not leaving ripe fruit on the tree or on the ground.
How to Protect Your Cherry Tree
Timing matters more than product choice. Cherry fruit flies lay eggs in the weeks before harvest, so any control strategy needs to be in place before fruit starts coloring. Sticky traps baited with pheromone lures are a practical monitoring tool. Some growers use sticky ball traps (similar to those used for apple maggots) wrapped in plastic wrap and coated with a tacky adhesive, then add a species-specific lure to attract males.
For small trees with manageable fruit counts, physically bagging individual fruit clusters with mesh bags or fine netting keeps egg-laying flies off the cherries entirely. Bird netting stretched over the whole canopy serves double duty, blocking both insects and birds.
Dormant oil sprays applied in late winter or early spring, before buds swell, smother overwintering insect eggs and scale insects on bark. Cold-pressed neem oil works as a general-purpose organic option during the growing season and is safe for use on fruit trees, vegetables, and herbs. For aphids and cherry slugs specifically, a strong blast of water from a hose knocks them off leaves, and insecticidal soap handles heavier infestations without harming beneficial insects like ladybugs, lacewings, and parasitic wasps, all of which prey on aphids naturally.
Encouraging those beneficial insects is one of the most effective long-term strategies. Planting flowering herbs and cover crops near your cherry trees gives predator insects habitat and alternative food sources, building populations that keep aphids and other soft-bodied pests in check season after season.