Do bugs lay eggs in blueberries? Uncovering the truth about common fruit pests

January 11, 2026 •

4 min read

Over 100 eggs can be laid by a single female blueberry maggot fly, which embeds its eggs inside ripening berries. So, the answer to the question, 'do bugs lay eggs in blueberries?' is a definitive yes, with several types of insects being the culprits.

Quick Summary

Yes, bugs like the spotted wing drosophila and blueberry maggot lay eggs inside ripening blueberries. This leads to mushy, rotten, and unmarketable fruit, but simple washing can mitigate risks for home consumers.

Key Points

Yes, it happens: Specific fruit flies like the Spotted Wing Drosophila and the Blueberry Maggot lay eggs inside ripening blueberries, not just overripe fruit.
SWD damage: Spotted Wing Drosophila eggs and larvae cause fruit to soften, dimple, and become susceptible to rot.
BM damage: Blueberry Maggot larvae consume the berry pulp, causing the fruit to become mushy and fall from the plant.
Identification: Look for small "stings" or breathing tubes, soft spots, premature ripening, or webbing between berries.
Easy cleaning: A vinegar or baking soda rinse is more effective than plain water at dislodging contaminants, and also extends the fruit's shelf life.
Not harmful: Accidentally consuming these larvae is not considered harmful to human health, though it is unappetizing.
Prevention: For gardeners, sanitation and pruning are key to reducing pest populations.

The reality of insect life cycles means that certain pests specifically target ripe or ripening fruit to lay their eggs, and blueberries are a prime target for several species. While unsettling to consider, this is a normal part of agriculture and natural ecosystems. Understanding the primary pests and their life cycles is the first step toward effective management and ensuring your fruit is clean and safe to eat.

Yes, Bugs Can Lay Eggs in Blueberries

Unlike many common fruit flies that only lay eggs in decaying fruit, some invasive and native species have evolved to target fresh, healthy fruit. The two most significant and well-documented pests responsible for laying eggs directly in blueberries are the Spotted Wing Drosophila and the Blueberry Maggot. Their larvae then hatch and feed on the fruit from the inside out.

Common Blueberry Pests That Lay Eggs

Spotted Wing Drosophila (SWD)

An invasive vinegar fly from East Asia, the female Spotted Wing Drosophila (Drosophila suzukii) uses her serrated ovipositor (egg-laying device) to cut into the skin of fresh, ripening blueberries to deposit her eggs. After only a few days, the larvae hatch and begin feeding internally. This feeding activity causes the fruit to soften, dimple, and become susceptible to decay and rot.

Signs of SWD infestation include:

Small, pin-prick-sized holes or depressions on the fruit surface from egg-laying.
Soft or mushy spots on otherwise fresh-looking fruit.
Wrinkled or collapsed berry skin.
A simple salt water “fruit dunk” test can reveal the presence of tiny, white larvae.

Blueberry Maggot (BM)

The adult Blueberry Maggot fly (Rhagoletis mendax) is a native pest that lays a single egg under the skin of a ripening berry. The larvae, which are small, white maggots, hatch inside the fruit and feed on the pulp. This internal feeding causes the berries to become soft and mushy, often causing them to drop prematurely. The infestation can go undetected until the fruit is harvested or eaten.

Signs of BM infestation include:

Infested fruit that ripens and softens prematurely.
Mushy berries with internal discoloration.
A significant number of fallen berries on the ground beneath the plant.

Cranberry and Cherry Fruitworms

These caterpillars are also known to infest blueberries. The Cranberry Fruitworm (Acrobasis vaccinii) lays eggs on unripe fruit, and the larvae enter through the stem end, feeding on several berries and tying them together with silk. The Cherry Fruitworm (Grapholita packardi) bores into the fruit, causing premature ripening and dropping.

How to Safely Clean Blueberries at Home

While finding a bug or larva in your fruit is an unpleasant experience, it's important to remember that such pests are not harmful if accidentally ingested. The main issue is spoilage. Thorough washing can mitigate the risk of contamination and remove external residues. The following steps can help ensure your fruit is clean:

The Water Rinse: Place blueberries in a colander and rinse gently under cold running water for at least 30 seconds, swirling them around to ensure all berries are exposed.
The Vinegar Soak: For a deeper clean, mix a solution of one part distilled white vinegar to three parts water. Soak the berries for 5-10 minutes, then rinse thoroughly under cold water to remove the vinegar taste. This method is also known to extend shelf life.
The Baking Soda Soak: Alternatively, use a baking soda solution by mixing one teaspoon of baking soda with two cups of water. Soak the berries for 10-15 minutes, and then rinse thoroughly.
Dry Completely: After washing, spread the berries in a single layer on a clean towel or paper towel and pat them dry completely. This prevents mold growth.

Comparison of Key Blueberry Pests


Feature	Spotted Wing Drosophila (SWD)	Blueberry Maggot (BM)
Adult Appearance	Small, brownish fly with red eyes; males have black spots on wings.	Small, black fly with a white dot on its thorax and 'F'-shaped wing bands.
Egg-Laying Location	Cuts into the skin of fresh, ripening fruit to lay eggs inside.	Lays a single egg under the skin of a ripening berry.
Larvae/Maggot	Tiny, white, cylindrical maggot; can be multiple per berry.	White, legless maggot; usually one per berry.
Damage	Causes fruit to become soft, mushy, and dimpled; multiple larvae accelerate spoilage.	Consumes fruit pulp, causing premature ripening, mushiness, and fruit drop.
Overwintering Stage	Adult flies can overwinter in sheltered areas.	Overwinters as a pupa in the soil below the plant.
Distribution	Invasive, widespread in many temperate fruit-producing regions.	Native to Eastern North America; established in certain regions.

Conclusion: How to Handle Bugs in Your Blueberries

The presence of bug eggs in blueberries, particularly from invasive species like the Spotted Wing Drosophila and native pests like the Blueberry Maggot, is a real and documented issue. However, it is a manageable one for consumers. Thoroughly washing your blueberries with water, or a vinegar or baking soda solution, can remove surface contaminants and larvae. For home growers, practicing good sanitation, proper pruning, and monitoring for pests are essential strategies for minimizing infestation. The occasional presence of a bug in fruit is a natural occurrence, and proper handling ensures you can continue to safely enjoy this healthy berry.

For more detailed information on managing these pests in commercial and home settings, resources like those from the Michigan State University Extension can be very helpful.

MSU Extension Bulletin on Blueberry Stem Gall Wasp: https://www.canr.msu.edu/blueberries/uploads/files/BlueberryStemGallWasp-WEB-final.pdf

Frequently Asked Questions

The primary culprits are the Spotted Wing Drosophila (SWD), an invasive fruit fly, and the native Blueberry Maggot fly. Other pests like the cranberry fruitworm also infest blueberries.

The eggs are very small and difficult to see. However, with magnification, you might be able to spot the two tiny white breathing tubes that extend from SWD eggs on the fruit's surface. The larvae (maggots) are white and can be seen once they hatch inside the fruit.

While unappetizing, accidentally eating larvae is not considered harmful to human health. The main issue for consumers is the mushy, unappetizing state of the infested fruit.

For a thorough cleaning, soak blueberries in a solution of one part white vinegar to three parts water for 5-10 minutes, then rinse completely under cold, running water. A baking soda soak is also an effective alternative.

If your blueberries are soft, dimpled, or mushy, it is a key sign of internal feeding by the larvae of pests like the Spotted Wing Drosophila or Blueberry Maggot.

No, organic fruit is also susceptible to pest infestation. Organic farming practices simply restrict the use of most synthetic pesticides. Thorough washing is still recommended for all produce.

For home gardeners, practicing good sanitation by removing fallen or rotting fruit is crucial. Pruning to maintain an open canopy can also discourage pests. Monitoring for pest activity with traps can help determine if further action is needed.

A rinse with cold, running water removes many surface contaminants, but it may not be sufficient for pests like SWD that lay eggs beneath the skin. A more effective soak with vinegar or baking soda is recommended for a more thorough clean.