Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/22/2001
Publication Date: N/A
Citation: Interpretive Summary: The Japanese beetle was introduced into the U.S. in the early 1900's and has spread through most states east of the Mississippi River. The larvae are the most serious pest of turf in the northeast and are a major problem in many regions. Beetles can be artificially dispersed in several ways, including shipment of nursery stock infested with larvae. Federal quarantines established in 1920 regulated the interstate movement of products and plants from beetle-infested areas. Although that quarantine was terminated in 1979, the U.S. Domestic Japanese Beetle Harmonization Plan established in 1992 and updated in 1998, provides guidelines for certification requirements to facilitate the marketing of nursery stock while assuring that pest risks are managed. Currently, the only acceptable treatment for field production stock sent from a beetle infested area to the western states is a dip treatment of chlorpyrifos. Tests conducted from 1996 through 1999 in nurseries in middle Tennessee found two new insecticides with the common names of imidacloprid and halofenozide performed very well when applied in May, June, or July. Using carbaryl as a soil and/or foliar application did not improve control over imidacloprid alone. Fipronil and thiamethoxam also demonstrated potential for larval control. Treatments with permethrin, tefluthrin, trichlorfon, bendiocarb and several biological control agents were ineffective. This information will be used by scientists to improve procedures for eliminating insects from nursery shipments. It can also be used by nursery personnel and regulatory officials throughout the U.S. to provide acceptable treatments for nursery stock transported from Japanese beetle infested areas.
Technical Abstract: Numerous field studies were conducted in commercial nurseries in Tennessee from 1996 through 1999 to evaluate chemical and biological treatments, application timing and rates and method of application for control of early instars of Japanese beetle. Insecticide treatments included bifenthrin, bendiocarb, chlorpyrifos, carbaryl, fipronil, halofenozide, imidacloprid, permethrin, tefluthrin, thiamethoxam and trichlorfon. Biological treatments included entomopathogenic nematodes (Heterorhabditis bacteriophora HP88 or H. marelatus), Bacillus thuringiensis Berliner subspecies japonensis Buibui strain and Beauveria bassiana (Balsamo) Vuillemin. All applications were applied on the soil surface or injected into the soil around the base of each tree. Tree type and size varied among and within tests, however, the sampling unit (61 cm diam root ball) remained the same throughout all tests. The biological treatments provided poor to moderate control of Japanese beetle larvae (0 B 75% control). Imidacloprid was the most frequently evaluated insecticide and achieved 91 - 100%, 87 B 100%, 83 B 100%, and 41 B 100% control with applications in May, June, July and August, respectively. Halofenozide treatments were never significantly different from imidacloprid treatments with one exception. Halofenozide provided 60 B 87%, 85 B 100%, and 82 - 92% control with applications made in June, July and August, respectively. Fipronil and thiamethoxam were evaluated to a lesser extent but both performed similarly to imidacloprid. Most other insecticide treatments were less successful in reducing numbers of Japanese beetle larvae and with few exceptions achieved less than 50% control.