Organophosphorus and synergised synthetic pyrethroid insecticides as grain protectants for stored sorghum |
| |
| Authors: | Mervyn Bengston Richard A H Davies James M Desmarchelier Mervyn P Phillips Bruce W Simpson |
| |
| Institution: | 1. Entomology Branch, Department of Primary Industries, Meiers Road, Indooroopilly, Brisbane 4068, Australia;2. ICI Plc, Plant Protection Division, Fernhurst, Haslemere, Surrey GU27 3JE, England;3. Division of Entomology, CSIRO, P.O. Box 1700, Canberra, ACT 2601, Australia;4. Bulk Grains Queensland, P.O. Box 136, Toowoomba, Queensland 4350, Australia;5. Agricultural Chemistry Branch, Department of Primary Industries, Meiers Road, Indooroopilly, Brisbane 4068, Australia |
| |
| Abstract: | A field experiment was carried out on bulk sorghum stored for 26 weeks in concrete silos in South Queensland. No natural infestation occurred. Laboratory bioassays of treated grain, in which malathion-resistant strains of insects were added to grain samples, indicated that all the treatments were generally effective. Deltamethrin (2mg kg?1)+piperonyl butoxide (8mg kg?1), fenitrothion (12mg kg?1)+fenvalerate (1 mg kg?1)+piperonyl butoxide (8mg kg?1), and fenitrothion (12mg kg?1)+phenothrin (2mg kg?1)+piperonyl butoxide (8mg kg?1) controlled typical malathion-resistant strains of Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst) and Ephestia cautella (Walker). Pirimiphos-methyl (6mg kg?1)+permethrin (1mg kg?1)+piperonyl butoxide (8mg kg?1) allowed some survival of adults and progeny production by S. oryzae after 12 weeks, and by one strain of R. dominica throughout. Chemical assays established that the residues and rates of breakdown of these grain protectants on sorghum conformed to the general pattern on other cereal grains. Residues at the conclusion of the experiment were below the individual Maximum Residue Limits recommended by the Codex Alimentarius Commission. |
| |
| Keywords: | |
|
|
