The letter from the MK re: Corn is only for kernels that were removed from the cob & rinsed.
Corn on the cob "COTC", always have been infested with thrips, they hide beneathe the kernels if you don't see them.
Corn on the cob infested with larvae of the European corn borer and the corn earworm has been intercepted frequently. Private shipments of plant material infested with the strawberry rootweevil destined from New York to points in Georgia, Minnesota, and Oregon have been halted. Iris rhizomes heavily infested with the iris borer have been found en route to points in California, Florida, and North Carolina.