Surface-applied insecticide treatments for quarantine control of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), larvae in field-grown nursery plants.
BACKGROUND
Japanese beetles, Popillia japonica Newman, are a quarantine challenge for nursery shipments from infested to non-infested states. Marathon (imidacloprid) and Discus (imidacloprid + cyfluthrin) are approved preharvest nursery treatments (US Domestic Japanese Beetle Harmonization Plan; DJHP). This study evaluated approved and non-approved (acephate, carbaryl, clothianidin, dinotefuran, halofenozide, thiamethoxam, trichlorfon) preharvest treatments, optimal rates (labeled 1x, 0.3-0.75 x or 2-3 x) and optimal timings (June, July, August and September) to control early-instar (grubs) P. japonica in field nurseries.


RESULTS
Most insecticides effectively reduced grub densities, except for acephate, carbaryl and trichlorfon. Clothianidin, thiamethoxam and halofenozide provided grub control equivalent to DJHP standards during most years. Across all test years and timings, percentage grub reductions were: Marathon (1x: 59.2-100; 3 x: 78.9-100), Discus (1x: 60.7-100), clothianidin (1x: 96.1-100; 3 x: 97.4-100), thiamethoxam (1x: 75.0-100; 3 x: 80.0-100), halofenozide (1x: 70.0-100; 3 x: 90.0-100) and dinotefuran (1x: 13.2-88.2; 3 x: 71.1-93.4).


CONCLUSIONS
July application was more consistent and effective than other timings, and higher rates (2x and 3 x) did not generally improve grub control. Overall, clothianidin, thiamethoxam and halofenozide (and dinotefuran applied in August) were equivalent to current DJHP standards. These insecticides may be suitable for DJHP Category 2 states, potentially lowering grower costs.
Oliver
Jason B
JB
Tennessee State University, School of Agriculture and Consumer Sciences, Otis L Floyd Nursery Research Center, 472 Cadillac Lane, McMinnville, TN 37110, USA. joliver@tnstate.edu
Reding
Michael E
ME
Youssef
Nadeer N
NN
Klein
Michael G
MG
Bishop
Bert L
BL
Lewis
Phil A
PA
D000818:Animals; D001517:Coleoptera / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D010944:Plants / Q000469:parasitology*; D011790:Quarantine; D013997:Time Factors
D007306:Insecticides