Rainfastness of Insecticides Used to Control Japanese Beetle in Blueberries

Abstract

Field-based bioassays were used to determine the relative impact of rainfall on the relative toxicity of four insecticides, phosmet, carbaryl, zeta-cypermethrin, or imidacloprid, from different chemical classes on adult Japanese beetles, Popillia japonica Newman, in highbush blueberries, Vaccinium corymbosum L. Bioassays were set up 24 h after spraying occurred and Japanese beetle condition was scored as alive, knockdown or immobile 1, 24, and 48 h after bioassay setup. All insecticides were significantly more toxic than the untreated control and zeta-cypermethrin consistently had the greatest toxic effect against the Japanese beetles. All insecticides experienced a decrease in efficacy after simulated rainfall onto treated blueberry shoots, although the efficacy of zeta-cypermethrin was the least affected by rainfall. This study will help blueberry growers make informed decisions on when reapplications of insecticides are needed in the field with the aim of improving integrated pest management (IPM).

Effect of simulated rainfall on the effectiveness of insecticides against spotted wing drosophila in blueberries

“…The application of simulated rainfall reduced the mortality to a varying degree depending on the level of rainfall and in some cases the type of insecticide used. These results are consistent with Hulbert et al (2012) who reported that simulated rainfall (range: 12.5-50.8 mm) decreased the efficacy of the phosmet, carbaryl, imidacloprid or zeta-cypermethrin treated blueberry shoots on adult Japanese beetle, Papilio japonica Newman. The data from the 2014 study showed lower mortalities with the higher levels of rainfall suggesting that higher levels of rainfall resulted in the removal of greater amount of residues from the plant surface.…”

“…Such a trend, however, was not observed in the 2015 study. Hulbert et al (2012) also did not observe the trend of higher wash-off with the higher levels of rainfall (range: 7.5-50.8 mm) on phosmet, carbaryl or zeta-cypermethrin but carbaryl.…”

Efficacy of insecticide residues on adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) mortality and injury in apple and peach orchards

“…The specific reason for this increase in mortality was not investigated, but does warrant further consideration including the effects of abiotic conditions such as temperature and rainfall. 22 In general, residual activity was not . Mean field mortality rates (± SE) of Halyomorpha halys by insecticides that yielded 100% mortality rate in a laboratory bioassay 9 across field trials tested in this study.…”

“…Interestingly, in the early season of 2012 the mortality rate for seven‐day old residues was higher than at three days for many insecticides. The specific reason for this increase in mortality was not investigated, but does warrant further consideration including the effects of abiotic conditions such as temperature and rainfall . In general, residual activity was not enhanced through the addition of an adjuvant.…”

Mass trapping designs for organic control of the Japanese beetle, Popillia japonica (Coleoptera: Scarabaeidae)

“…Management options for P. japonica in organic crop production systems are limited and include microbial and botanical insecticides . In North America, materials that can be applied against P. japonica larvae include entomopathogenic nematodes ( Heterorhabditis bacteriophora ) and the bacterium Paenibacillus popilliae ( Bacillus popilliae ) .…”