Toxicity of Insecticides in a Glass-Vial Bioassay to Adult Brown, Green, and Southern Green Stink Bugs (Heteroptera: Pentatomidae)

Abstract

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest of citrus crops worldwide. A large number of insecticides have been used to manage D. citri in Florida. Therefore, insecticide resistance could become an important problem facing citrus production. Monitoring insecticide susceptibility in populations of D. citri and providing a technique to use as an early warning is needed so citrus producers can modify chemical control strategies for this pest in Florida. The objective of this study was to develop a simple and fast tool to determine insecticide resistance in D. citri and apply it to commercial citrus production in Florida. LC50 and LC95 estimates were determined for 8 commonly used insecticides on a susceptible laboratory population of D. citri 24 h after treatment in a residual contact bottle assay. Five to 7 concentrations of each insecticide were tested. The LC50 values (and 95% fiducial limits) ranged from 0.06 (0.02-0.26) to 0.80 (0.26-2.46) ng/µL for each insecticide tested. Exposure time-mortality indices were determined for 0, 10, 100, 1,000, and 10,000 ng/µL concentrations of each insecticide in a laboratory susceptible strain. Knockdown was assessed after 15, 30, 45, 60, 75, 90, 105, and 120 min. Complete knockdown (100.0%) occurred within 60 min for dimethoate, fenpropathrin, imidacloprid, bifenthrin, and flupyradifurone at the 10,000 ng/µL concentration. For spinetoram, 86.7% knockdown occurred within 120 min at 10,000 ng/µL. For sulfoxaflor and cyantraniliprole, 44.0 and 42.6% knockdown, respectively, occurred within 120 min at 1,000 ng/µL. We also developed a bottle bioassay to survey field populations of D. citri for insecticide resistance in central Florida. Exposure time-mortality indices developed in the laboratory were used to assess susceptibility of 1 laboratory and 4 field populations of D. citri after 15, 30, 50, 75, 90, 105, and 120 min of exposure at the 10,000 ng/μL concentration of various insecticides. Little to no evidence of resistance was detected for bifenthrin, dimethoate, imidacloprid, and fenpropathrin in central Florida. Our investigation demonstrated that a bottle bioassay is suitable for assaying insecticide resistance in D. citri adults under laboratory and field conditions. It should be a flexible tool for rapid testing of insecticide resistance in possible cases of insecticide failure. Its simplicity should allow trained professionals to rapidly monitor for insecticide resistance in commercial settings where "hot spots" of D. citri populations may occur.

Influence of Soybean Planting Date and Maturity Group on Stink Bug (Heteroptera: Pentatomidae) Populations

“…In addition to green and southern green stink bugs, a separate analysis was conducted for brown stink bugs. This analysis was conducted because brown stink bugs are more difÞcult to control with insecticides than green or southern green stink bugs (Willrich et al 2003, Snodgrass et al 2005. Other stink bug species observed in the plots included Thyanta spp.…”

Toxicity and risk of permethrin and naled to non-target insects after adult mosquito management

“…The toxicity of permethrin to house crickets is similar to that of adult tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois), green stink bugs, Acrosternum hilare (Say), and southern green stink bugs, Nezara viridula (L.), using methods similar to our study (Snodgrass 1996;Snodgrass et al 2005). The LC 50 values for technical grade permethrin ?…”

Susceptibility of Southern Green Stink Bug and Redbanded Stink Bug to Insecticides in Soybean Field Experiments and Laboratory Bioassays

“…1). Adult vial test bioassays similar to those described by Plapp et al (1987), Willrich et al (2003), and Snodgrass et al (2005) were used to determine susceptibility of southern green and redbanded stink bug adults to six insecticides: four pyrethroids (bifenthrin, cyfluthrin, cypermethrin, and lambda-cyhalothrin) and two organophosphates (acephate and methamidophos). Stock solutions of insecticides were prepared by dissolving technical-grade insecticide (Chem Services, West Chester, PA) in acetone.…”

“…Field experiments in Arkansas, Louisiana, and Texas showed the southern green stink bug was consistently easier to control with pyrethroids and organophosphates compared to the brown stink bug (Emfinger et al 2001, Gable et al 2004, Greene et al 2004, Way et al 2005. Snodgrass et al (2005) reported more susceptibility in green and southern green stink bugs to organophosphates and pyrethroids compared to the brown stink bug. Similar results were reported in Louisiana (Emfinger et al 2001, Willrich et al 2003.…”