If you leave the package in the cupboard for a long time, the insects will escape and infest other foods and, eventually, the entire cupboard. Insects Preferring Humid Weather You can expect specific and somewhat unique insect problems in hot, humid weather. Controlling these pests with insecticides is usually futile. Instead, you should lower the relative humidity with dehumidifiers. These are small, wingless, jumping insects.
Some species are chalky white, others are black.
They are common pests in greenhouses, damp basements and storage rooms, where they feed on microscopic fungi growing on walls, boxes, pallets and around drains. They are frequently found living on decaying organic matter in potted houseplants. Allowing the soil surface to dry usually reduces their numbers. Some members of this group have wings, however, the common nuisance pest found in damp areas is wingless, a frequent pest in libraries, museums, warehouses, railroad cars and trucks. It also occurs in areas where dusty products are manufactured or processed, such as grain and flour mills, and dried milk processing plants.