Susceptibility to Insecticides Used for Control of <I>Piezodorus guildinii</I> (Heteroptera: Pentatomidae) in the United States and Brazil

Abstract

Limited information exists on the insecticide susceptibility of redbanded stink bug, Piezodorus guildinii (Westwood) (Heteroptera: Pentatomidae), despite its impact on soybean, Glycine max (L.) Merr., production in Brazil and the United States. Therefore, this study set out to 1) determine baseline levels of susceptibility to currently recommended pesticides using topical and vial bioassays, 2) determine the levels of esterase activity in populations in the United States and Brazil, and 3) compare control among products in field trials. In topical bioassays conducted in the United States using technical grade materials, the LC50 values of lambda-cyhalothrin, acephate, and methamidophos were 4-25, 141-295, and 40-151 ng per insect, respectively. The LC50 values of imidacloprid and thiamethoxam were 11 and 27 ng per insect, respectively. In vial bioassays conducted in the United States using technical grade materials, the LC50 values of cypermethrin, acephate, and methamidophos were 0.4-0.9, 3.8, and 1.6 microg per vial, respectively. In topical bioassays conducted in Brazil by using commercially formulated products, the LC50 values of acephate, methamidophos, endosulfan, and imidacloprid were 0.90-1.9, 0.4-0.6, 1.5-6.6, and 0.2-0.3 microg per insect, respectively. In vial bioassays conducted in Brazil using commercially formulated products, the LC50 values of endosulfan, methamidophos, and lambda-cyhalothrin were 4-32 and 2-24 microg/cm2 for thiamethoxam and imidacloprid. Esterase activity in Louisiana (United States) populations ranged from 251 to 658 nmol alpha-naphthol formed/min/mg protein. Esterase activity levels in Londrina (Brazil) populations averaged 163 nmol/min/mg. In field tests, P. guildinii in Louisiana were controlled by organophosphates thiamethoxam and imidacloprid and in Brazil, with combinations of neonicotinoids and pyrethroids.

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

“…This study confirms reports from agricultural consultants and producers that the redbanded stink bug is less susceptible than the southern green stink bug to numerous insecticides. In field studies from 2003 to 2006, Baur et al (2010) reported redbanded stink bug control of 81 and 69% for acephate and methyl parathion, respectively. In the current study, control by acephate (86%) was similar but slightly greater than for methyl parathion (82%).…”

“…In the current study, control by acephate (86%) was similar but slightly greater than for methyl parathion (82%). This may be attributed to the use of field rates approximately 25% greater than rates used by Baur et al (2010). Baur et al (2010) reported that control of redbanded stink bugs with pyrethroids (bifenthrin, cyfluthrin, gamma-cyhalothrin, lambda-cyhalothrin, and zetacypermethrin) ranged from 52 to 80%.…”

“…This may be attributed to the use of field rates approximately 25% greater than rates used by Baur et al (2010). Baur et al (2010) reported that control of redbanded stink bugs with pyrethroids (bifenthrin, cyfluthrin, gamma-cyhalothrin, lambda-cyhalothrin, and zetacypermethrin) ranged from 52 to 80%. Similar results were seen in the current study, with all pyrethroids providing 80% control of redbanded stink bug.…”

“…Baur et al (2010) reported the initial baseline toxicity data on Louisiana redbanded stink Baur et al (2010). Both pyrethroid and organophosphates have been used to control redbanded stink bug in Louisiana since it became a pest.…”

“…Currently labeled insecticides to control redbanded stink bug in Brazilian soybeans include organophosphates (acephate, methamidophos, and trichlorform), carbamate (carbaryl), organochlorine (endosulfan), and neonicotinoid + pyrethroid pre-mixture (thiamethoxam + lambdacyhalothrin) (Anonymous 2011). Baur et al (2010) reported baseline toxicity data for Louisiana redbanded stink bugs to the insecticides acephate, cypermethrin, and methamidophos in glass-vial bioassays and reported the first field-efficacy data for control of redbanded stink bug in soybean, but made no direct comparisons to other stink bug species. In those experiments, control of redbanded stink bugs was estimated at only 50 to 80% with the insecticides tested.…”