Susceptibility of Euschistus heros and Dichelops furcatus (Hemiptera: Pentatomidae) to Selected Insecticides in Brazil

Abstract

Euschistus heros (Fabricius, 1798) and Dichelops furcatus (Fabricius, 1775) are key pests of agricultural crops in Brazil. Chemical insecticides are the main control tactic used against these species. Here, we investigated the susceptibility of E. heros and D. furcatus from distinct regions to the mains insecticides used to stink bugs control in Brazil. Field populations of these species were collected throughout the 2017–2019 crop seasons and insects were exposed to insecticides in dip-test bioassays using fresh green bean pods. Populations of E. heros exhibited low variation in the susceptibility to acephate (LC50 = 172.2 to 1,008 µg a.i. per ml), and thiamethoxam (LC50 = 28.8 to 433.9 µg a.i. per ml); resistance ratios were less than 5.9- and 15.1-fold, respectively. In contrast, these populations had higher variation in the susceptibility to bifenthrin (LC50 = 26.7 to 636.1 µg a.i. per ml) and lambda-cyhalothrin (LC50 = 10.0 to 636.1 µg a.i. per ml); resistance ratios reaching 23.8- and 63.6-fold, respectively. Susceptibility monitoring data indicated a higher susceptibility of E. heros to the manufacturers field-recommended rates of acephate, lambda-cyhalothrin + thiamethoxam, and bifenthrin + acetamiprid than lambda-cyhalothrin. Populations of D. furcatus exhibited low variation in the susceptibility to acephate (LC50 = 219.2 to 614.1 µg a.i. per ml), bifenthrin (LC50 = 62.8 to 197.4 µg a.i. per ml), and lambda-cyhalothrin (LC50 = 189.5 to 2,538 µg a.i. per ml); resistance ratios were less than 13.4-fold. In summary, populations of E. heros are less susceptible to pyrethroids, while populations of D. furcatus have similar susceptibility to the insecticides evaluated.

Monitoring Resistance of Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) to Insecticides by Using Encapsulated Artificial Diet Bioassay

“…The resistance of E. heros to insecticides has not been detected using current bioassay methods, but control failures have been reported. In Brazil, failure to control E. heros populations has been reported for beta-cyfluthrin, bifenthrin, lambda-cyhalothrin (pyrethroid), and imidacloprid (neonicotinoid) [ 19 , 20 , 21 , 22 ]. Besides, there are numerous reports of farmers facing issues in controlling this species in soybean cultivation.…”

“…In Brazil, E. heros control measure failures have been reported for several insecticides, including beta-cyfluthrin, bifenthrin, lambda-cyhalothrin (pyrethroid), and imidacloprid (neonicotinoid) [ 19 , 20 , 21 , 22 ]. Until now, cases of E. heros resistance to endosulfan (cyclodiene), monocrotophos (organophosphate), methamidophos (organophosphate) [ 23 , 24 ], and imidacloprid [ 25 ] were detected using the tarsal contact method.…”

Potential ofFicus caricaextracts againstEuschistus heros: Toxicity of major active compounds and selectivity against beneficial insects

“…Over recent years, the global utilization of conventional pesticides has grown dramatically, and the indiscriminate use of these chemical products has led to undesired consequences for ecosystems and human health 1–3 . Currently, the most prevalent form of controlling E. heros still is the application of a small number of synthetic molecules (mainly organophosphates, pyrethroids, and neonicotinoids), which are known to selected resistant populations 4–7 and cause undesired sublethal effects 8–12 that may contribute to pest outbreaks and can harm nontarget organisms such as pollinator bees and natural enemies 13–15 …”

Synergism and unintended effects of the association between imidacloprid and sodium chloride (NaCl) on the management of Euschistus heros

“…23,25,26 The frequent overuse of neonicotinoid insecticides against this species leads to unintended sublethal effects 27,28 and control failures due to insecticide resistance. [21][22][23]29 In this study, we assessed the toxicity and evaluated whether the sublethal exposure of E. heros to imidacloprid [at 0.126 μg active ingredient (a.i.) cm −2the equivalent to 3% of the field rate recommendation] alone, or mixed with low NaCl concentration (0.5% w/v), could cause any unintended effects on the survival and reproductive responses of these insect pests.…”

“…This species is the prevailing stink bug pest species of South American soybean‐growing fields 23,25,26 . The frequent overuse of neonicotinoid insecticides against this species leads to unintended sublethal effects 27,28 and control failures due to insecticide resistance 21–23,29 …”