Globally invasive scarabs – from the Midway Islands to Milan, Italy

Scarab beetles are viewed in various parts of the world as sacred, beautiful and interesting, or destructive and repulsive. In Japan, one or two Japanese beetles, Popillia japonica Newman, are considered lucky because of their beautiful dress, but the eight million Japanese beetles captured in traps in northern Italy probably did not bring forth cries of bella, bella!! Traps and lures are at the forefront of any eradication program to delineate the population. For instance, California deploys over 10,000 (2/mi²) Japanese beetle traps per year to find any invading beetles, and then uses 50 traps per mile² to map the distribution. However, mass trapping of beetles has not been a successful eradication method, and that tactic plus microbial pesticides failed to keep the Japanese beetle from reaching most of the Azores Islands. On the other hand, lures were an important component in removing the “Midway emerald beetle”, Protaetia pryeri (Janson), with program using traps, a larval insecticide and destruction of larval habitat on the islands of the Midway Atoll. Normally, killing larvae with an insecticide, or some other agent, is the backbone of scarab eradication programs. A procedure of treating 200 meters around every trap find has recently eradicated populations of the Japanese beetle in western Colorado and Utah, and has eradicated beetle populations in Oregon, California, and New Mexico in the past. It is possible that mating disruption with the racemic blend of Japonilure, could be an important addition to eradication efforts and replace foliar insecticide treatments.