Pesticide risks Pesticides can kill desirable organisms as well as pests. For example, broad spectrum insecticides may kill pollinators such as bees or lady bugs, which eat garden aphids Pesticides enter the food network and through biological magnification may concentrate to toxin levels in secondary and tertiary consumersPesticide Risks Pesticides can kill desirable organisms as well as pests. For example, broad spectrum insecticides may kill pollinators such as bees or lady bugs, which eat garden aphids. Pesticides enter the food network and through biological magnification may concentrate to toxin levels in secondary and tertiary consumers