West Nile Virus West Nile virus (WNV) is a potentially serious illness. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. This fact sheet contains important information that can help you recognize and prevent West Nile virus. Click for more info Pyrethrum Pyrethrum is a botanical insecticide produced primarily from the flowers of Tanacetum cinerariaefolium, which is a species of the chrysanthemum plant family. It is found mainly in tiny oil-containing glands on the surface of the seed case in the tightly packed flower head and is the plant’s own insecticide that has evolved to keep insects away. Click for more info Permethrin Like the use of any pesticide, they are safe only if precautions are known about and followed. Permethrin is a broad spectrum synthetic pyrethroid insecticide. Permethrin has been around since the 1970’s and is widely used today in public health, home pest control, forestry, agriculture and head lice control. Click for more info