Author
MANNION, C - TENN STATE UNIV | |
NIELSEN, D - OSU/OARDC-ENTOMOL DEPT | |
Klein, Michael | |
MCLANE, W - USDA-APHPIS |
Submitted to: Southern Nursery Association Proceedings
Publication Type: Proceedings Publication Acceptance Date: 8/15/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Japanese beetle larvae, and other white grubs, are a threat to nursery production in the eastern United States. In addition to damaging plant material, larvae in root stock create regulatory concerns and prevent movement of plants to uninfested areas. Tests were conducted in Ohio during the early spring of 1996 to evaluate the effects of two insecticides on the survival of white grubs following dip treatments of balled and burlapped trees. Dursban eliminated larvae from 24-32 inch rootballs with sandy soil from northern Ohio, and from 24 inch heavy clay rootballs from southern Ohio. These results provide growers with a "last resort" treatment which will allow them to ship nursery stock from fields infested with Japanese beetle larvae to uninfested areas. Technical Abstract: Numerous midwestern and western states have quarantines or other certification requirements to prevent the introduction of Japanese beetle larvae in nursery stock. Tests were conducted on the efficacy of dipping balled and burlapped trees which were naturally infested with white grubs. Two insecticides (chlorpyrifos and isophenphos) were evaluated with 24-32 inch rootballs from sandy soil in northern Ohio, and 24 inch rootballs from a heavy clay soil in southern Ohio. Trees were dipped for 1, 2, or 5 minutes. Chlorpyrifos was the most effective material, providing 100% control after five weeks in both types of soil following dips or either 2 or 5 minutes. These results provide an emergency treatment for infested root stock, but additional work is needed to further refine the techniques and establish patterns of phytotoxicity. |