How to prevent drugstore beetles in the house?

How to prevent drugstore beetles in the house?

Drugstore beetles feed on Chinese herbs and plant-based dry goods. Prevention requires a comprehensive approach covering purchase, storage, and environmental management.

Purchase and pre-treatment

• Do not put newly purchased plant-based dry herbs directly into storage cabinets.
• First freeze at -18°C for 48 hours to kill any hidden eggs.
• After freezing, inspect to confirm no live insects before storing.

Airtight storage

• Store all dry herbs in sealed glass jars or food-grade plastic containers.
• Do not use original plastic or paper bags — these do not keep beetles out.
• Store each type of herb separately to prevent cross-contamination.
• Place a small food-grade silica gel desiccant pack inside each container to keep dry.
• If a package is found infested, seal and isolate it immediately; do not open it nearby to prevent adults from flying out and spreading.

Environmental management

• Keep storage cabinets dry; beetles prefer humid environments.
• Regularly clean out debris and powder from cabinets; do not leave food residues.
• Do not store bulk herbs in cabinets for long periods; consume them in a timely manner.
• Keep cabinets ventilated to reduce dust accumulation.

Chemical control

• If drugstore beetles have been found once, apply environmental treatment to the entire storage area.
• After emptying the storage area, vacuum thoroughly, keep dry, and treat interior walls, shelves, and baseboards with insecticide.
• Once dry, the powder forms a protective layer to prevent dormant larvae or eggs from re-emerging.