D3254: Efficacy of soil-applied insecticides for control of wireworms

This study investigated the influence of insecticides on plant emergence in two field trials
conducted in sugarcane plots inoculated with wireworm (Coleoptera: Elateridae) larvae.
Wireworms are sporadic pests of sugarcane that feed on seed cane at planting and have
potential to reduce plant populations. Wireworms had been managed using organophosphate
insecticides, a potential risk for human life and beneficial insect populations. Alternative
insecticides are explored: a neonicotinoid insecticide, thiamethoxam (Platinum®, Syngenta),
broflanilide (Nurizma®, BASF), phorate (Thimet®, ADAMA) and an experimental
insecticide (A22466). Trials were conducted at the USDA Sugar Research Unit North Farm
in Schriever, LA, and the LSU AgCenter Sugar Research Station in St. Gabriel, LA. In each
experiment, one larva per row-foot was placed in each plot and covered with soil. Treatments
were applied over the top of the seed cane with a back-pack sprayer. Platinum and different
rates of A22466 were tested in Schriever, while thimet and different rates of broflanilide were
tested in St. Gabriel. Both trials included an infested control and an uninfested control. In the
Schriever trial, Platinum and the highest rate of A22466 showed significant difference in
plant population in fall 2021, but no differences were detected in 2022 plant stands, stalk
weights, or cane tonnage. In the St. Gabriel trial, differences in fall 2021 plant populations
were not detected among treatments trial, but in 2022 thimet and highest concentrations of
broflanilide were detected among treatments on tons per acre. Results suggest new
chemistries show promise in protecting plant cane stands from wireworm damage.