Granary Weevils

Facts, Identification, & Control

Scientific Name

Sitophilus granarius

Appearance

What Do They Look Like?

Granary Weevil
Granary Weevil image licensed under CC

  • Size: They measure up to 5 mm in length.
  • Color: Granary weevils (also known as wheat weevils) are typically brown in color.
  • Characteristics: They feature highly pronounced pitted patterns on their heads. They are equipped with vestigial wings and are incapable of flight. They are similar in appearance to rice weevils, although their wings exhibit no spotting.

How Did I Get Granary Weevils?

These stored grain pests almost solely travel through infested grains or grain products such as oats, wheat, or dry pasta. Adult females burrow into seeds to lay their eggs and then seal the openings.

Once the eggs hatch, mature granary weevil larvae feed inside the grain or seeds, thus causing the damage. About one month after the female adult beetle lays her batch of eggs, the insect completes its life cycle, newly formed adults emerge and then spread to other products to lay eggs; thus, beginning the cycle all over again.

How Serious Are Granary Weevils?

The pests contaminate the products they infest, but in general, they aren’t harmful to humans if infested products are thrown out. These insects can’t bite or sting and don’t transmit disease. In addition, they feed solely on grain. They do not eat fabric or cause structural damage. Removing infested items is central to granary weevil control.

Signs of a Granary Weevil Infestation

Sightings of adults and their exit holes from the grains indicate activity.

How Do I Get Rid of Granary Weevils?

What Orkin Does
Your local Orkin technician is trained to help manage granary weevils and similar pests. Since every building or home is different, your Orkin technician will design a unique program for your situation.

Orkin can provide the right solution to keep granary weevils in their place…out of your home, or business.


Behavior, Diet, & Habits

What Do They Eat?
Commonly called the granary weevil, the wheat weevil is best known for its destructive potential in agricultural communities. Since they are unable to fly, the pests prefer stored grains over those found in fields.

Reproduction
Using their plump mandibles, females puncture grain kernels in order to deposit eggs. Eggs hatch into larvae, whose nutrition is secured by the content of the kernels. Granary weevil pupae emerge within five weeks and mature within five months.

More Information
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