How to Prevent Corn Bugs in Storage

Growers and commercial handlers across the United States are noting an increased focus on grain quality, with high standards and regulations for commodities hitting the market. Maintaining quality in stored corn is key to competing in today’s market.

Direct insect feeding, particularly from the elusive weevil, reduces market value, causing contamination and deterioration of stored corn. Maintaining value of corn in storage calls for a proactive approach to controlling insects, utilizing a combination of integrated pest management (IPM) and grain protection products.

Let’s take a look at which insects impact stored corn and the best pest control solutions for corn bugs in bins and elevators.

  • Weevils: Weevils, such as maize weevils, rice weevils, and granary weevils, can be the most damaging and hardest to treat insects for your stored corn, as the larvae actually grow from eggs deposited inside kernels leaving a hollowed-out kernel. Adult- weevils feed on whole and broken kernels, and damaged grain often has a “shot hole” appearance.
  • Indian Meal Moths: This pest is often identified when the larvae produce dense webbing that binds to food fragments. Adult Indian Meal Moths are often seen flying in the vicinity of a grain bin, while larvae can be spotted climbing up walls inside bins.
  • Lesser Grain Borers: Signs of infestation from the lesser grain borer include fragmented kernels with a powdery residue. A sweet musty odor is often associated with this insect, along with a “shot hole” appearance in damaged grain.
  • Sawtoothed Grain Beetles: Overheating of grain is a common infestation sign from the Sawtoothed Grain Beetle, with a visible population build-up.

For a comprehensive list of the insects that impact stored corn, and to learn more about their appearance, life cycles, and habits, make sure to visit our insect-id, designed to help you quickly identify stored grain insects and offer advice to help prevent or control insects in your stored corn.

Prevention and Control

To control these hard-to treat insects, Central Life Sciences recommends cleaning and treating empty bins with a tank-mix of Diacon® IGR PLUS and PBO-8® Synergist.

Tank-mixing not for you? No problem! Gravista® Insecticide has made post-harvest grain treatment even easier. The 3-in-1 combination eliminates labor intensive tank-mixing and provides long-term control on stored product insects.

Central Life Sciences also brings a boost to for short-term grain storage and rescue treatments. centynal-synergized combines both an adulticide and a synergist, to help control even the toughest stored product insects.

After treating, monitor your corn throughout the storage period, using your selected grain protectants to help suppress insect populations. As part of a comprehensive IPM strategy, we also recommend aerating grain during warm weather periods of storage to help control moisture and temperature, which can be a breeding ground for corn bugs.

To learn more about Bug Free Grains and the comprehensive line of products offered by Central Life Sciences, visit


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