Maggot Infestation In Mushrooms: How Many Is Too Many?

Mushrooms are a type of fungus that grows in damp, dark places. While they are a delicacy for many, mushrooms can also be a breeding ground for insects, particularly maggots. Maggots are the larval stage of flies and other insects, and they can often be found in mushrooms, especially older ones. While the idea of consuming maggots may be unappetizing, it is not uncommon to find insects in our food, and the FDA has established guidelines for acceptable levels of these natural contaminants. In fact, according to the FDA, Americans consume an average of 1 to 2 pounds of flies, maggots, and mites each year without even knowing it. While maggots in mushrooms may be unpleasant, proper harvesting, storage, and cooking techniques can help reduce their presence and make mushrooms safe for consumption.

Maggots in mushrooms are normal

It is normal to find maggots in mushrooms, especially older wildcrafted mushrooms. Mushroom tissue is similar to animal tissue, and a decaying mushroom can support maggots. Maggots are the larval stage of flies and other related insects. Flies lay their eggs inside mushrooms, and these eggs hatch into maggots. This is why it is important to harvest mushrooms promptly and cook them or dehydrate them, as this kills the bugs. If you leave freshly picked mushrooms in the fridge for a few days, the eggs will hatch, and the maggots will grow.

While finding maggots in your mushrooms can be unnerving, it is not unusual for maggots to be present in food. In fact, the US Food and Drug Administration (FDA) allows for a small number of insects to remain in food. The FDA has established acceptable levels of "natural contaminants" in our food supply, which can include bugs, mould, rodent hairs, and maggots. For example, the FDA allows for up to five fly eggs and one maggot per 100 grams of tomato juice, and up to 15 fly eggs and one maggot per 100 grams of tomato paste.

Mushrooms are actually granted more leeway when it comes to maggots, with the FDA allowing for 20 maggots "of any size" per 100 grams of drained mushrooms or 15 grams of dried mushrooms. While it may be unsettling to think about, Americans on average ingest 1 to 2 pounds of flies, maggots, and mites each year without knowing it, and the FDA considers this to be safe.

It is important to note that while maggots in mushrooms are normal, you should still take steps to properly clean and prepare your mushrooms before consuming them. This can include rinsing or soaking the mushrooms, although it is recommended to not soak them for more than 5-10 minutes to avoid affecting their texture. Additionally, some people recommend using saltwater to soak mushrooms, as this can help to drown any bugs that may be present.

How to prevent maggots in mushrooms

Maggots in mushrooms are more common than you might think. Mushroom tissue is similar to animal tissue, and decaying mushrooms can support maggots. Maggots are usually found in older mushrooms, and they can render the mushrooms inedible.

To prevent maggots from infesting your mushrooms, it is important to act quickly. Mushrooms have a short window of time between being ripe for the picking and becoming too large for consumption. Foraging mushrooms and immediately cooking them is a good way to kill bugs and larvae. If you are not planning to cook them right away, you can blanch them before dehydrating them to kill any bugs.

If you are growing mushrooms, you can take steps to prevent pests from infesting your crop. Flies, such as cecid flies, phorid flies, and sciarid flies, are common mushroom pests. The adult flies are rarely seen, but their larvae can infest mushrooms and spread throughout a mushroom farm. To prevent flies from infesting your mushrooms, you can pasteurize the soil before planting. Raising the temperature of the soil to 140 degrees Fahrenheit for at least four hours will kill insects, nematodes, pest fungi, and other pests. However, it is important to note that pasteurization will not prevent invaders from outside sources.

Additionally, you can take steps to control the environment around your mushrooms. Flies thrive in warm, humid environments, so keeping the area well-ventilated and cool can help deter them. You can also use physical barriers, such as fine mesh screens, to keep flies out. Regularly inspecting your mushrooms for signs of infestation, such as small holes or discolouration, can help you catch problems early on.

How to remove maggots from mushrooms

Maggots in mushrooms are a common problem, especially for those who grow their own mushrooms. The first step to removing maggots from mushrooms is to identify the type of maggot and the extent of the infestation. Some maggots are more visible than others, with the Cecid fly maggot appearing as white or orange legless larvae, while the Phorid fly maggot is creamy-white.

If you are growing mushrooms, the best form of pest control is prevention. Mushroom flies, which lay the eggs that become maggots, thrive off mycelium and compost. They are also capable of surviving cold temperatures. To prevent an infestation, growers can use natural predators such as praying mantises, predatory mites, parasitic wasps, and Venus fly traps. Coffee grounds and tobacco can also be introduced into the growing space to deter pests. Pasteurising the substrate is another effective prevention method.

For those who are dealing with an active infestation, there are a few options for removal. One method is to dry the mushrooms, as maggots need moisture to survive. Drying the mushrooms over a screen will ensure that any bugs that crawl out fall through and away from the mushrooms. After fan-drying, the mushrooms can be placed in a desiccator for a few days to ensure they are completely dry. Another method for removing maggots from mushrooms is to soak the mushrooms in salt water, which causes the maggots to float to the top. A cold water salt bath soak can also be used for outdoor mushrooms, followed by a rinse in the sink, fan drying, and then desiccation to complete the drying process.

While it is not recommended to eat mushrooms infested with maggots, some people choose to do so. If you decide to eat infested mushrooms, it is important to first remove any soft, discolored, spongy, or funny-smelling parts of the mushroom. It is also recommended to soak the mushrooms in salt water to remove the maggots before cooking.

Maggots in mushrooms: are they harmful?

Maggots in mushrooms are a common occurrence, especially in older wild mushrooms. While the idea of consuming maggots may be unappealing, they are generally not harmful to human health. In fact, the practice of eating insects, or entomophagy, is widespread around the world, and some startups and restaurants in the US have even launched bug-related food products.

The US Food and Drug Administration (FDA) acknowledges the presence of insects and other natural contaminants in our food supply. The FDA's Center for Food Safety and Applied Nutrition has established acceptable levels of "defects" for various food products, including canned or dried mushrooms. According to FDA guidelines, an average of 5 or more maggots that are 2 mm or longer per 100 g of drained mushrooms or 15 g of dried mushrooms is considered adulterated. These guidelines were established in 1995 and have been revised multiple times to ensure food safety.

Mushroom growers can employ various methods to control and eradicate pests. Proper sanitation practices include pasteurizing the soil medium before planting a new crop, which involves raising the temperature to 140 degrees Fahrenheit for at least four hours to eliminate insects, nematodes, and other pests. Additionally, there are insecticidal sprays and soaps available that can be applied to the walls and floors of the mushroom house to kill soft- and hard-bodied insects.

To avoid consuming maggots, it is recommended to harvest mushrooms promptly and cook them immediately. Soaking or rinsing mushrooms before use can also help remove bugs, although it may not always be effective. While maggots in mushrooms may be unpleasant, they are typically not harmful, and proper harvesting, storage, and cooking practices can minimize their presence.

Are there maggots in other foods?

Maggots are the larval stage of flies and other related insects. They are soft-bodied, legless, and worm-like, with a reduced head that can retract into the body. Maggots are commonly associated with rotting flesh, tissue debris, and decaying organic matter. While they are often considered pests, some people intentionally consume them as a source of protein and good fats.

The presence of maggots in food, including mushrooms, is not uncommon. In fact, the US Food and Drug Administration (FDA) allows for a small number of insects and other "natural contaminants" in our food supply. For example, the FDA guidelines state that up to five fly eggs and one maggot per 100 grams of tomato juice are acceptable. Similarly, canned or dried mushrooms are allowed to have an average of five or more maggots that are 2mm or longer per 100 grams of drained mushrooms or 15 grams of dried mushrooms. These guidelines were established in 1995 and have been revised several times since then.

While the consumption of maggots may be safe in some cases, there are also health risks associated with it. Eating live maggots or maggot-infested food can cause bacterial poisoning, transmitting bacteria such as Salmonella and Escherichia coli to humans. Additionally, some people may be allergic to maggots or experience respiratory and asthmatic symptoms when handling them. Therefore, it is generally recommended to cook or process mushrooms and other foods to kill any potential maggots or insect eggs before consumption.

Maggots have been found in various foods, including apples, tomato products, peanut butter, and even soup. In some cultures, the intentional consumption of insects and maggots is common. For example, Casu marzu, a traditional Sardinian cheese, is known for containing thousands of live maggots. The cheesemaker removes the outer crust during production, inviting flies to enter and lay their eggs. The resulting larvae break down the cheese, and their excrement gives the cheese its unique flavor. However, due to health risks, the European Food Safety Authority has banned the sale of this cheese.

Frequently asked questions