Grain weevil. Fighting at home

The grain weevilis a beetle whose adult individuals and larvae feed on grains and dry grain foods, thereby damaging our pantries and kitchens. In this article you will learnwhat the grain weevillooks like, how to recognize it and how it differs from rice weevil and swollen weevil. Discover the best, natural ways tofighting grain weevil at home

Corn weevil - Sitophilus granarius
Fig. Sarefo, CC BY-SA 3.0, Wikimedia Commons

What damage does grain weev do?

Grain weevil(Sitophilus granarius) belonging to the weevil family is a dangerous pest causing large losses in grain storage. It also appears in our homes. We can come across this beetle in flours, groats, pasta, as well as bran or breakfast cereals.The female grain weevil bites a channel in the grain and lays an egg in itThe egg hatches a larva, which after about 40 days turns into an adult beetle. The adult form of the grain weevil emerges from the grain through the bitten hole.
In the absence of grain or corn, female weevils can lay eggs in flour products such as pasta and dried bread.Products contaminated by weevils are unfit for consumptionProducts with particles of weevil chitinous shell after eating cause various inflammations and intestinal disorders. Allergens contained in this beetle and its faeces have a negative effect on the respiratory system and may aggravate the symptoms of asthma (this is a threat mainly to workers in bakeries and grain warehouses).

What does grain weev look like?

The grain weevil is a beetle that can reach 2-5 mm in length . The elongated, brown or black body is covered with a chitinous shell. The head is stretched out into a long snout. The corn weevil does not fly. Beetles are resistant to low temperatures but do not like light.

Grain weevil versus rice weevil

Grain weevil is easy to confuse with rice weevil(Sitophilus oryzae). However, the rice weevil is lighter in color - reddish and covered with short bristles. It has well-formed wings. It requires a higher temperature to develop than the grain weevil. It thrives best at a temperature of around 30 ° C. Adult insects die quickly when they lack food.

Grain weevil and the swollen

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The grain weevil is also sometimes confused with the swelling . Opuchlaki are small beetles with a characteristic snout. Like grain weevils, they cannot fly. In the swollen, the fused wing covers are covered with lighter stripes and spots. "

Opuchlak and the grain weevil - comparison
Fig. pixabay.com

Opuchlaki feed on garden plants. Adult beetles attack the above-ground part of plants, gnawing holes in their leaves. On the other hand, the larvae of the oysters feed in the ground on the roots of plants. From the garden, the swollen also go to homes. When brought along with plants and soil, they can feed on potted plants.
Often, they enter houses alone, appearing mainly near windows and doors leading to the garden or terrace. Unexpectedly spotted on the wall or floor,may be confused with grain weevil

Grain weevil - fighting

This voracious beetle is difficult to get rid of becausethe life cycle of the grain weevilis inside the grains. In addition, the weevil can live for up to 2 years, and the female can lay up to 300 eggs per year.
In the fight against the grain weevil , first of all, you should focus on prevention - hygiene and tight packaging and containers for food storage.This is especially important, because it is difficult to buygrain weevil remediesin living rooms. The commercially available preparations are used for professional control of this pest in warehouses and grain silos. They are not suitable for use in apartments.
After finding the presence of grain weevilin food products, remove them from the kitchen as they are unfit for human consumption. Kitchen cabinets should be thoroughly washed, preferably with a disinfectant. Other products, in which the presence of the grain weevil has not been found, should be viewed frequently, moved and tapped (the weevil does not like noise and rarely nests in noisy places). It is also a good idea to hide uninfected food in the refrigerator with a temperature of around 0 ° C, as this temperature is not conducive to the development of grain weevil.

Note!
As most of the grain weevil's life cycle goes inside the infected kernels (from the egg to the larva stage to the adult stage), it is very difficult to identify infected grain products (you cannot see pests hidden inside the grains until the adult beetles have left their hiding places).Therefore, any products suspected of coming into contact with grain weevil should not be eaten. Alternatively, they can be used as grain for birds or animal feed.

Scientists have been studying the effects ofnatural agents for repelling and eliminating grain weevil for yearsThese are preparations of herbs, oils, infusions. As a result, it was found that the powders from dried plants such as: tansy, yellow sweet clover, yarrow, purple lilac, marsh grass, Indian honey, field mint, peppermint, marshmallow, elderberry, elderberry, mugwort have the greatest repelling and fighting effects. Wormwood, caraway, Dalmatian chrysanthemum, large-leaved mullein, sage, narrow-leaved lavender, black pepper, paprika and fragrant cinnamon.
Oils from long turmeric leaves, eucalyptus and green mint used on blotting paper discs arrangedin places where weeviloccur, they have a strong repellent and insecticidal effect.
Adding powdered basil plants, geranium, caraway, mullein and thyme to the food of insects causes significantmortality of female grain weevils , and thus the disappearance of the entire population.
So it is worthwhile put various herbal scents in kitchen cupboards and pantries if we wantto avoid the appearance of grain weevilin our stocks.

MSc Eng. Anna Błaszczak