Maize weevil
Scientific name
Sitophilus zeamais Motschulsky
Classification
Primary pest; grain feeder
Order: Coleoptera
Family: Curculionidae
Acronym: SZE
Description
- Adults are identical in external appearance to the rice weevil (Sitophilus oryzae); dissection required to distinguish between the species.
- Adults are reddish brown beetles with a characteristic long weevil snout and have 4 yellow to red spots on the elytra.
Images
Similar species
- Granary weevil (Sitophilus granarius),
- Rice weevil (Sitophilus oryzae) – morphologically nearly identical
Commodities affected
- Grain, pasta
Signs of infestation
- Damaged kernels with ragged holes
- Increased heat and humidity in pockets of grain
Damage
- Damaged kernels with ragged holes
- Larvae feed internally and newly emerged adults leave a ragged exit hole and will also feed on the damaged kernel.
- Maize weevil infestations produce heat and moisture.
How to control
Geographic range
- Is abundantly distributed in tropical environments throughout the world, where it is able to infest standing crops
- Is less common in temperate zones and, in Canada, has only been found in Ontario and Quebec
Where found
- Is found in granaries, stores, elevators
- Tends to aggregate within grain bulks, making populations difficult to detect
Life history
- Adults can fly.
- Adult beetles are long-lived (3 to 6 months or more).
- Adult females lay eggs singly by first chewing a small hole in the grain, then depositing the egg into the hole then sealing with a mucus plug
- Larvae hatch and feed internally within the kernel.
Not what you're looking for?
Start over again from the Insect identification key page.