Bacillus thuringiensis is a naturally occurring soil bacterium commonly known as Bt. It is a biological pesticide (biopesticide) used as a spray or dust and also in several genetically engineered plants. The plants have a gene from Bt inserted into their own genetic material. This new gene produces a natural protein that kills insects after the protein is ingested. The toxins are specific to a small subset of insects. Cotton has been genetically altered to control the tobacco budworm, bollworm and pink bollworm. Potatoes have been altered to control the Colorado potato beetle. A new hybrid of Bt corn, altered to be resistant to the European corn borer, became available for the 1997 planting season. Bt degrades rapidly to non-toxic compounds. It is not known to present any human or animal hazards. However, recent reports suggest that it may harm certain beneficial insects, such as monarch butterflies. Pest resistance management (PRM) plans are required by the Environmental Protection Agency as part of the registration.