Biology of the navel orangeworm,<i>Paramyelois transitella</i>(Walker), on almonds and walnuts in northern California

Abstract

the Federal Bureau of Entomology took one adult in a light trap near Tempe, Arizona. This was the first recorded collection of the navel orangeworm in the United States. He further noted that the navel orangeworm came into prominence in 1921. He stated that during July of that year, navel oranges in the Salt River Valley of Arizona were falling in greater abundance than usual, and many of them were infected with a blackrot known as Alternaria citri Ellis and Pierce. A survey of the groves showed that practically all the diseased fruits were infested with caterpillars of the navel orangeworm. Because the disease and the caterpillars were found only in Washington and Australian navel oranges, the larvae were thought to be responsible for the presence of the disease. Mote also called attention to the fact that the Arizona Commission of Agriculture and Horticulture, in a letter, offered California authorities an opportunity to investigate the problem and simultaneously prohibited the movement of Arizona navel oranges into California. This embargo was supplemented by the California authorities with instructions to all quarantine inspectors and guardians to refuse to admit navel oranges from Arizona. A quarantine order was not promulgated, for fear of causing unnecessary injury to the Arizona citrus industry. Mackie and Jacobsen (1930) mentioned that the above order was superseded on March 11,1927, by Quarantine Circular No.7, with no changes being made in regard to excluding fruit from California.