title: Synergistic Effects of Oxygen on Phosphine and Ethyl Formate for the Control of Phthorimaea operculella (Lepidoptera: Gelechiidae).
abstract: Phosphine (PH3) and ethyl formate (EF) are two potentially powerful postharvest fumigant insecticides. We investigated the effectiveness of both PH3 and EF as fumigants at all developmental stages of the potato tuber moth Phthorimaea operculella Zeller, and we also studied the synergistic effects of these fumigants under controlled atmospheres of 50 and 80% oxygen (O2). The larval stage of P. operculella was the most susceptible to fumigation with PH3 at both 5°C and 20°C. All of the developmental stages showed greater susceptibility to PH3 at 20°C than at 5°C, whereas the susceptibility of adult P. operculella to this fumigant was not affected by temperature. The toxicity of EF did not differ with temperature for any of the P. operculella developmental stages. The atmospheric oxidation of PH3 increased the toxicity of this fumigant toward all developmental stages at both temperatures. In contrast, no differences in toxicity were observed for oxidized EF compared with EF alone at any developmental stage. In conclusion, using fumigation tests, we showed that atmospherically oxidized PH3 was much more effective against P. operculella than PH3 alone, demonstrating a synergistic effect for this fumigant and O2. Therefore, treatment with PH3 and high concentrations of O2, as described in this study, could be useful for managing the postharvest pest P. operculella.
authors.affiliation: Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea. khkim@chungbuk.ac.kr.
authors.forename: Hyun Kyung
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Seon-Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Highland Agriculture Research Center, Rural Development Administration, Pyeong-chang 232-955, Republic of Korea.
authors.forename: Ju-Il
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Animal and Plant Quarantine Agency, Plant Quarantine Technology Center, Suwon, Republic of Korea.
authors.forename: Jeong-Oh
authors.initials: JO
authors.lastname: Yang
authors.affiliation: Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Hyun-Na
authors.initials: HN
authors.lastname: Koo
authors.affiliation: Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea. khkim@chungbuk.ac.kr.
authors.forename: Gil-Hah
authors.initials: GH
authors.lastname: Kim
mesh_terms: D000818:Animals; D004357:Drug Synergism; D005563:Formic Acid Esters; D005651:Fumigation; D007814:Larva; D009036:Moths; D010063:Ovum; D010100:Oxygen; D010720:Phosphines; D011679:Pupa; D018675:Toxicity Tests
chemical_list: D005563:Formic Acid Esters; D010720:Phosphines; C510888:ethyl formate; C044646:phosphine; D010100:Oxygen
keywords: Phthorimaea operculella; controlled atmosphere; ethyl formate; oxygen effect; phosphine