 Many States have enacted laws which have created State Boards of Entomology.The interstate spread of pests has been prevented to a large extent through State regulations requiring that nursery stock be free from infestation, and these are enforced by rigid State inspection.In November, 1916, the occurrence of the pink bollworm in the Laguna district of Coahuila, Mexico, within 200 miles (322 km) of the Texas border, was discovered, and an embargo was placed upon the importation of Mexican cotton.