The Agriculture Department has ordered an immediate quarantine for 13 states to help prevent the further spread of a tiny killer mite that threatens the U.S. bee industry.

The restrictions ban the shipment from those states of bees and apiary equipment, said Larry B. Slagle, acting associate administrator of the department's Animal and Plant Health Inspection Service.States affected by the quarantine are: Florida, Illinois, Maine, Michigan, Mississippi, Nebraska, New York, Ohio, Pennsylvania, South Carolina, South Dakota, Washington and Wisconsin.

Of the major honey producing states, only California and North Dakota so far remain unaffected by the mites, whose scientific name is Varroa Jacobsoni. The female is about one-twentieth of an inch in diameter, and the male is somewhat smaller.

The mites were discovered in the United States last September in a Wisconsin apiary and since have spread to the 12 other states.

"Varroa mites can be spread by the movement of queen bees, package bees, hives, pollen, honeycomb with brood cells, and apiary equipment and vehicles," Slagle said. "Under our regulations, these articles will be prohibited from moving interstate from quarantined areas unless certain conditions are met."

The female Varroa mite lays 3 to 20 eggs in the protective comb cell of a developing bee. Young mites emerge and suck the blood of the bee larvae, killing or causing them to be deformed and useless to the hive in which case they are killed by the worker bees.

If agency inspectors determine that there is no risk of mites, they can issue certificates allowing the movement out of the quarantined states, Slagle said. In other cases, a "limited permit" may be issued.