t that they came to the port in some soil used as ballast in the bottom of a cargo ship. Since this introduction the black fire ant has not spread as rapidly as the red imported species. By 1953 (first official USDA survey) the red imported fire ant had spread to over 100 counties in 10 states. Today it is prevalent throughout the southeastern US and has moved into Texas, New Mexico. Arizona and California.
Natural movement of fire ants is limited to mating flight or by rafting during period of flooding. However, the rapid movement of these species across the South and westward is mainly associated with human activity. In this case the initial spread of these ants in the southeastern US was thought to be due to movement of sod and potted ornamental plants. This inadvertent movement of S. invicta and S. richteri was noted by the U.S. Department of Agriculture in 1953 when a direct link was established between commercial plant nurseries and the spread of imported fire ants. In response to mounting public pressure, the U.S. Congress appropriated $2.4 million in 1957 for control and eradication efforts. As part of an overall plan quarantine was imposed to retard or prevent the artificial dissemination of these now notorious pests. On May 6th 1958, regulations governing the movement of nursery stock, grass sod and some other items were instituted through the Federal Quarantine 301.81. By that time, however, imported fire ants had moved into 8 southern states. This spread, although slowed considerably by federal regulations and climatic conditions, continues even today. In recent years, isolated infestations of imported fire ants have been found as far west as New Mexico, Arizona California and as far north as Kansas and Maryland. In the case of California it is thought that the spread of these ants into this state was due to movement of bee hives as most initial infestations were found in around orchards and other situations where bees were moved into these areas for crop pollination. Based on USDA prediction these an