California Citrus Exporters:

The California Citrus Quality Council (CCQC) is sending this notice to remind packinghouses that Korean quarantine officials have asked the industry to control Fuller rose beetle (FRB) eggs in citrus shipped to Korea. APHIS and Korea's quarantine officials will meet in July to discuss citrus issues including FRB and California red scale (CRS). Currently, growers are required to (i) skirt prune, (ii) control weeds and (iii) make one foliar insecticide application to control FRB.

While these are the current minimum requirements, CCQC is sending this message to update the industry on Beth Grafton-Cardwell's latest research that indicates that the best FRB control is achieved with a combination of early season ground applications of bifenthrin followed by foliar insecticide treatments.

Beth Grafton-Cardwell provided the following information about FRB control:

The goal is to reduce the population by skirt pruning, in combination with ground (soil) or trunk sprays with bifenthrin, or foliar insecticide sprays applied during the period of time when adults might lay eggs that remain viable at harvest. In the San Joaquin Valley, more than 50 percent of the beetles emerge from the soil in August, so that is a key month for control.

Apply a ground or trunk bifenthrin spray before peak emergence (June or July). Foliar sprays are more important to apply August through October after peak emergence, because the eggs deposited earlier in the season hatch before harvest. When practicing season-long suppression, follow these guidelines in the San Joaquin Valley (in southern California, a similar strategy should be used but applications should be applied one month later):

  • If three treatments are planned, they should be applied in June (soil), August (foliar) and October (foliar).
  • If two treatments are planned, then apply a ground (soil) or foliar spray in August and a foliar treatment in October.

A substantial reduction in beetle numbers will likely take several years with two to three treatments per year. It is essential to combine skirt pruning with one or more of the other strategies (ground sprays, trunk sprays, foliar insecticide sprays, or a combination of these) to improve effectiveness.

Please contact me by telephone at (530) 885-1894 or via e-mail at if you have questions or need additional information.

Regards,

James R. Cranney, Jr.

California Citrus Quality Council

853 Lincoln Way

Auburn, California 95603