A 20 year effort to allow avocados from Hawaii has paid off - the USDA lifted a ban that's been in place since 1992, after fruit fly larvae was found in a Sharwil avocados packing house in Hawaii. Avocados have been grown in Hawaii since being introduced by Australia in the 1950s.

To prevent accidental introduction of oriental fruit flies to the U.S. after the larvae discovery, previous rules required fumigation and cold treatments that ruin the quality of the fruit.

But scientists have determined that the avocados are poor hosts for fruit flies, lawmakers wrote in their letter.

The new guidelines allow Hawaii to ship to 32 mainland U.S. states and the District of Columbia between November and March. California and Florida, the largest mainland producers, are not on that list of states.

Move over, Haas: USDA clears way for Hawaii to ship avocados to 32 mainland US states By Oskar Garcia, The Associated Press