EMERGENCE OF PESTICIDE-RESISTANT PESTS Exposure to a pesticide will not make an individual pest resistant; it will likely kill it. However, if a few pests survive because they happen to be naturally resistant, they will breed and their offspring (most of which are also pesticide resistant) will make up the next generation. Over time, the original pesticide will no longer be effective and will have to be applied at a higher dose or a different pesticide will have to be used. Application of a pesticide might even increase the size of the pest population by killing the predators that eat the pests.