The plant disease citrus greening has hit Florida hard. Growers in other citrus-producing states, like Arizona, see it as a warning.
Researchers in San Luis are collecting new data on a wasp that may help slow the spread of the disease.
The parasitic wasp Tamarixia radiata is so small, scientists can ship 200 of them in a vial about the size of a photo film canister.
Bobby Baker, a technician with the USDA, has received weekly shipments of the vials for more than a year.