There are over 100 different insects and mites found infesting grain in Wisconsin. About 90% are small beetles while most of the remaining species are caterpillars and moths. These insects and mites can be divided into three general groups depending on the types of feeding, potential damage, and the environments they prefer. One of the major problems is that these insects look so similar, but control options will differ depending on what insect is associated with the stored grain. Not all infestations need to be fumigated or sprayed.