The spiraea aphid, Aphis spiraecola Patch, which previous to 1924 was known only on species of Spiraea in the northern United States, in that year appeared in mass infestations on citrus trees in Florida and Cuba, causing enormous damage by distorting and resetting the young growth. By 1926 it had spread to Puerto Rico, attacking not only various endemic trees and plants, but being implicated in the transmission of a new virus disease of papaya. By 1928, it was reported on citrus from Honduras in Central America, and it has since dispersed to Costa Rica, and on a great variety of hosts to California, Oregon, and Washington on the Pacific Coast.
Manual of the botany of the northern United States.
