Insecticidal Effects of Fumigants (EF, MB, and PH3) towards Phosphine-Susceptible and -Resistant Sitophilus oryzae (Coleoptera: Curculionidae)

Abstract

This study was conducted to evaluate the insecticidal effects of ethyl formate (EF), methyl bromide (MB), and phosphine (PH3) fumigants against PH3-susceptible and -resistant strains of the rice weevil (Sitophilus oryzae), a major rice pest. The highest lethal concentration time 50 (LCt50) values of the PH3-susceptible strains were 255.797, 21.104, and 6.171 mg h L−1 for EF, MB, and PH3, respectively, at pupal stage. The highest LCt50 values of the PH3-resistant strains were 149.028 and 48.170 mg h L−1 for EF and PH3, respectively, at late larval stage, and 43.520 mg h L−1 for MB at pupal stage. In comparison to the susceptible strains, the PH3-resistant strain collected in South Korea had a resistance level 4 to 56 times higher. Use of the major quarantine fumigants EF, MB, and PH3 indicated the existence of PH3-resistant rice weevils in South Korea for the first time.

Ethyl formate dilution in carbon dioxide for fumigation control of the brown marmorated stink bug Halyomorpha halys, Stål (Hemiptera: Pentatomidae)

“…The mean air temperature in the chambers was calculated across all trials; deviation in temperature was assumed to follow a normal distribution with the estimated margin of error reported as 10 ± 0.5 °C (x±2s). 34 Consistent with its well-documented potential for sorption, 13,17,[20][21][22]26,[35][36][37][38][39][40] [EF] did not remain constant over the duration of fumigation, therefore (Ct) m (Table S1) values seeded the exposure-mortality regression modeling and projected exposure outputs (Ct) p , where p indicates a modelpredicted value (i.e. probit analysis in this case) (Table 1).…”

Fumigant Activity of Ethyl Formate against the Chestnut Weevil, Curculio sikkimensis Heller

“…For controlling coleopteran pests of stored products, Agarwal, et al [ 28 ] reported that 24 h of fumigation at 22–24 °C using EF at 25–30 g/m 3 without apples could achieve the complete control of eucalyptus weevils, Gonipterus platensis (Coleoptera: Curculionidae), while EF at 40 g/m 3 under the same conditions, with a 90–95% filling ratio of apples, could achieve complete control. Kim, et al [ 29 ] reported that the LCT 99 values for Sitophilus oryzae (Coleoptera: Curculionidae) exposed to EF at 20 °C were 775.48 and 449.20 g·h/m 3 for phosphine-susceptible and -resistant late larvae, respectively. Asimah, et al [ 30 ] reported that fumigation using 190 g/L of liquid EF (CT value = 1322.12 g·h/L) for 40 h was sufficient to control all the stages of Tribolium castaneum (Coleoptera: Tenebrionidae) and Lasioderma serricorne (Coleoptera: Anobiiadae) in cocoa beans.…”

Comparative Proteomics Analysis of Phosphine-Resistant and Phosphine-Susceptible Sitophilus oryzae (Coleoptera: Curculionidae)

“…The PH 3 -resistant strain of S. oryzae was obtained from Plant Quarantine Technology Center (Gimcheon, South Korea). The resistance ratios indicated that the lethal concentration time (LCT) 50 value was >56.1-fold higher in the PH 3 -resistant strain (16.550 mg•h/L) of S. oryzae than in the PH 3 -susceptible strain (0.295 mg•h/L) [24]. All the strains of S. oryzae were successively cultured on rice grains at the Chungbuk National University (Chungcheongbuk-do, Korea) under controlled conditions (25 ± 1 • C, 80% relative humidity, and 16L:8D photoperiod).…”