Does Freezing Kill Weevils in Flour, Rice, Beans, and Pasta?


It’s early in the morning, and just as you are about to open the window, you see about ten or more weevils on the windowsill. You go down to make breakfast, and when you open the box, there are weevils in the powder. Why are there bugs all over the house, and what can I do to stop them?

Freezing is the easiest and effective way to kill a weevil. When flour, rice, beans, and pasta is left in the freezer for 3-7 days, it will kill both the adult weevil and its eggs. 

Weevils come into a house through dry foods sold in cardboard or plastic sealed bag packages. The unseen and undetected eggs are inside the dry food and hatch in your home after a few days. They then become adult weevils that fly and crawl their way around the house. 

How Long to Freeze Flour to kill Weevils

The Flour Weevil is a tricky pest as it can live and breed in the same bed of flour its whole life without leaving as an adult.  Freezing the flour ensures no eggs remain and the visible weevil is strained out before storing properly. 

Before Freezing the Flour

Weevils are present in flour when you buy a bag in the grocery. The female weevil will deposit its eggs in the crevices of a carton of flour. Within a month the eggs become larvae and will feed through the flour until it molts to become a pupa, then into an adult weevil

The Weevil will live for 1-3 years in a warm and humid storage place is They will feed and breed in the same bag of flour. When you buy flour, there are eggs in the carton that may have gotten in while in the flour mill, storage area, or from the grocery. 

During Freezing the Flour

Flour must be taken out of the box or plastic bag and placed in an air-tight plastic container or freezer bag. Flour that is frozen for a minimum of 2-5 days will kill both the adult and its eggs. 

After Freezing the Flour

Put the flour on a sifter to separate the powdered flour from the dead weevils. The flour is transferred to an air-tight and hard-cased container to protect it from a new threat of weevil visitors. 

How Long to Freeze Rice to Kill Eggs

The Rice Weevil if not contained will settle in different parts of the house with its ability to fly.  The adult weevil cannot survive when frozen, but many say the eggs will stay dormant while frozen then hatch when it’s a warmer temperature.

Before Freezing

The rice weevil starts as larvae that hatch its eggs on wheat grains, seeds, or nuts. In 1-3 weeks, it will pupate into an adult. Within three days, the flying rice weevil can lay 300-600 eggs anywhere in the house while it lives for 3-6 months. 

The rice weevil is the most dreaded because they don’t stop on the rice grain. Once they get out of the rice box, it starts to attack the They like the cotton fabric of a shirt or even furniture. They munch on dried plants or home ornaments. They eat fresh fruits like apples, grapes, and pears. 

During Freezing

Rice must be taken out of the thick plastic bag or carton and placed in an air-tight plastic container or freezer bag. Rice that is frozen for a minimum of 4 days will kill the adult and possibly its eggs. 

Others say that the rice weevil is temperature tolerant and will lie dormant while frozen. As soon as it warms up, the eggs and the pupae will develop. 

After Freezing

Scatter the rice grains in a flat tray to dry out and air any moisture from the freezer. When you are confident that rice is dried. Put the rice grains on a sifter or a sieve to separate any weevils. Transfer to an air-tight hard-cased plastic container or a well-sealed rice container. 

As there are claims that the eggs of a rice weevil do not die while frozen, so it’s imperative to check for weevils every time you get rice to cook. 

How Long To Freeze Beans To Kill Bugs

The eggs of the Bean Weevil remain inside the pod to feed on as it grows to an adult.  Unless frozen, the beans without any hole may still have the eggs or larvae of the weevil. Even if you soak the beans in water, only the adult weevils will sloat while the larvae get their protective cover from the bean coat.  

Before Freezing the Beans

The larvae or pupa of a bean weevil is already in the bean pod when you buy a bag of beans. The female weevil lives for 21-80 days and can lay as much as 60-100 eggs in a pile of beans or a bean seed plant or bean foliage. 

They are internal feeders and feed on the same seed until it exits from the seed coat. It will fly out to mate and look for other piles of beans to lay its eggs. When packed beans are in bags, there is no way to detect if there are eggs in the beans until a few days later or when the beans are soaked in water.

During Freezing the Beans

The beans placed must be placed in an air-tight plastic container or freezer bag. It is frozen for a minimum of 3-7 days to kill both the adult and its eggs. 

After Freezing the Beans

Scatter beans in a flat tray with a paper napkin underneath to absorb moisture when beans are thawing while adjusting to room temperature. You must check that beans are dry and will not have condensation when transferred to an air-tight bottled jar or air-tight hard-cased container.

How Long To Freeze Pasta To Kill Bugs

The Pasta Weevil or the pantry monster will crawl out and take any chance it gets to crawl back into any dried food to make a meal out of it.  Unless frozen, the eggs which have been quietly hidden by the mother will move on to become part of the pantry pests.

Before Freezing the Pasta

The pasta or pantry monster is a crawling pest and cannot fly. The female weevil lays its eggs inside a pasta kernel 254 times in its lifetime of 8 months. The mother is territorial and protects the eggs by chewing a hole in the grain or pasta then seals it with a gelatinous secretion. 

The eggs were already packed straight from the pasta plant and will continue to feed on it until it becomes an adult. The weevils were inside the box of pasta noodles when you bought it from the grocery. The weevils will crawl out of the box when they are adults to find other nourishment.

During Freezing The Pasta

Pasta like macaroni, lasagna, or spaghetti must be taken out of the carton box and placed in a freezer bag. Pasta is frozen for a minimum of 4 days and will kill the adult and possibly its eggs. 

After Freezing The Pasta

Lay the pasta noodles in a tray to air dry before transferring them into an air-tight glass container where the other weevils cannot enter. Pasta must dry out without any moisture otherwise, the noodles will become soggy and spoil.

Related Questions

How to get rid of weevils?

Aside from freezing the dry goods for a few days, you can use the heating process. Pop the dry food in the Microwave for five minutes in a high-temperature setting.

How to prevent weevils?

Transfer dry food such as cereal, flour, cornstarch, rice, oatmeal, and all kinds of beans immediately into air-tight hard-cased containers to prevent any growth or infestation.

Does freezing kill insect eggs?

Some insect eggs will remain dormant by freezing the first time. Wait a week for eggs to hatch and freeze the dry goods again for another 30 days.

Photo credit: ©canva.com/baibaz, ©canva.com/showcake

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