|Reding, Michael - Mike|
Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/28/2006
Publication Date: 2/1/2007
Citation: Oliver, J., Reding, M.E., Klein, M.G., Youssef, N., Mannion, C., Bishop, B. 2007. Chlorpyrifos immersion to eliminate third instar Japanese beetle (Coleoptera:scarabaeidae) in balled and burlapped trees and subsequent treatment effects on red maple. Journal of Economic Entomology. 100(2):307-314. Interpretive Summary: The Japanese beetle (JB) is a quarantine pest of nursery crops. Disruption of nursery trade by quarantines can have serious economic impacts on the U.S. green industry, which contributed about $300 billion dollars and 1.9 million jobs to the U.S. economy in 2002. Quarantine of the JB in nursery crops is regulated at the state level by following the guidelines in a cooperative agreement called the Japanese Beetle Harmonization Plan (JBHP). Currently, there are very few treatment methods for control of JB in nursery stock that meet the JBHP standards. The most effective approved method for balled & burlapped (B&B) nursery stock is dipping the root balls in a solution of Dursban, an organophosphate insecticide. In this research we were testing reduced doses of Dursban in dips for efficacy at controlling JB in B&B nursery stock. One way to reduce the impact of a pesticide on the environment and increase worker safety is to reduce the dose applied. We found that doses as low as 12.5% (1/8) of the standard dose still provided 100% control of JB in 12- and 24-inch root balls. If these lower rates are adopted by the JBHP, quarantine treatments for controlling JB in nursery crops will be much safer for workers; more environmentally friendly than current standard practices because the amount of insecticide used will be reduced; and using less insecticide will reduce the grower's cost for controlling JB.
Technical Abstract: This study examined chlorpyrifos immersion of balled and burlapped (B&B) root balls for elimination of third instar Japanese beetle (JB) (Popillia japonica Newman) and for phytotoxicity on red maple (Acer rubrum L.). Trees were harvested as 45 and 60 cm diameter B&B and immersed in chlorpyrifos at U.S. Domestic Japanese Beetle Harmonization Plan rate (0.24 kg ai/100 liters) or lower at 0.015 (Federal Imported Fire Ant Quarantine rate), 0.03, 0.06, and 0.12 kg ai/100 liters. The 0.03, 0.06, and 0.24 kg ai rates provided 100% control of JB grubs in both 45 and 60 cm B&B. The 0.015 and 0.12 kg ai chlorpyrifos rates were 100% effective in three tests. However, in another test, 0.015 and 0.12 kg ai chlorpyrifos treatments had four (93% control) and one (98% control) grubs recovered, respectively. Test plants originated from fields with soil texture classification of loam, silt loam, or clay loam. Clay content of loam soils (i.e., 7 - 27% clay) did not preclude chlorpyrifos from providing near 100% JB grub control. Post-treatment observations of field planted 45-cm diameter B&B red maple indicate first year trunk diameter growth reduction from chlorpyrifos, but effects were unapparent in later years. Chlorpyrifos rate or root ball size had no measured affect on canopy/internode growth or visual phytotoxicity rating in any year. In conclusion, chlorpyrifos dip rates >= 0.03 kg ai are near 100% effective, satisfying JB Harmonization standards, while rates < 0.24 kg ai lower cost, reduce worker exposure, and lessen potential environmental contamination.