Assessment of the grain protectants chlorpyrifos‐methyl plus bioresmethrin, fenitrothion plus (1R)‐phenothrin, methacrifos and pirimiphos‐methyl plus carbaryl under practical conditions in Australia

Abstract

Methacrifos (22.5 g t-l) and the three protectant combinations chlorpyrifos-methyl ( l o g t-l) plus bioresmethrin (1 g t-l), fenitrothion (12 g t-l) plus (1R)-phenothrin (2 g t-l) and pirimiphos-methyl (4 g t-I) plus carbaryl(8 g t-1) were each applied to grain that was stored in at least 15 silos. Grain temperature and levels of protectant were regularly monitored, and samples f r o m 12 storages using each treatment were taken f o r laboratory assays against Rhyzopertha dominica and Tribolium castaneum. Grain condition did not deteriorate during storage. Grain remained free of insects in 60 of the 63 storages treated; partial failure in the other 3 storages was attributed to low or irregular levels of protectant. The mean and range of residue values of all protectants were recorded as a function of time and the mean observed values corresponded to predicted values. In laboratory 27 1 Pestic. Sci. 0031-613X/87/$03.50 0 Society of Chemical Industry, 1987. Printed in Great Britain

Synergized Bifenthrin Plus Chlorpyrifos-Methyl for Control of Beetles and Psocids in Sorghum in Australia

“…Protectant residues on the sorghum were more variable over time than residues from similar trials with wheat (e.g., Desmarchelier et al 1987), but followed patterns found with protectants tested on sorghum (Bengston et al 1984). Bengston et al (1984) explained that commercial sorghum includes considerable dust from abraded cuticle and epidermal tissues, and that these tissues have higher residues resulting from direct spraying of insecticide to the external layer of the kernel.…”

“…The application rate for bifenthrin (0.5 mg/kg) was well below the temporary Maximum Residue Limit (2 mg/kg) established by the Australian National Registration Authority for the purpose of grain protection. The relative stability of residues in these trials, especially chlorpyrifos-methyl residues, contrasts with wheat trials in Australia in which residue levels typically declined during storage (e.g., Desmarchelier et al 1987).…”

Avaliação de inseticidas no controle de Sitophilus oryzae (L.) (Coleoptera: Curculionidae), e Rhyzopertha dominica (Fab.) (Coleoptera: Bostrichidae) em arroz armazenado

“…Os resultados obtidos no controle de R. dominica com fenitrothion, são discordantes daqueles obtidos por Desmarchelier et al (1987) e Bareth & Gupta (1989a), os quais atestaram a eficácia deste inseticida contra este inseto. No entanto, são semelhantes aos obtidos por Bareth & Gupta (1989b), os quais observaram a eficiência de deltametrina até os 150 dias após o tratamento.…”

“…R. dominica, também é praga muito séria para grãos armazenados, sendo considerada primária, e ocasionalmente encontrada infestando espigas no campo (Christensen 1982). Desmarchelier et al (1987), concluíram que carbaril, pirimifos-metil, fenothrin plus e fenitrothion, foram mais eficazes do que metacrifos e bioresmetrina plus e chlorpirifósmetil no controle de R. dominica aplicados em grãos armazenados na Austrália. Rao & Rao (1988) determinaram a CL50 para deltametrina e fenpropathrin em adultos de S. oryzae, criados em quatro cereais distintos.…”

Resíduos de fenitrotion e esfenvalerato em grãos de milho e trigo, em alguns de seus produtos processados e sua ação residual sobre Sitophilus oryzae (L., 1763), Sitophilus zeamais Motsch.,1855 (Coleoptera: Curculionidae) e Rhyzopertha dominica (Fabr.,1792) (Coleoptera: Bostrichidae)

“…Naquelas condições, depósitos inferiores e grande variação com relação à dosagem teórica do inseticida freqüentemente são encontrados (VARDELL et al, 1973; ROWLANDS, 1975;DESMARCHELIER et al, 1987; REDLINGER et al., 1988; WHITE; SINHA, 1990;ACDA et al, 1994). Com o objetivo de melhorar a qualidade da pulverização gerada pelos bicos hidráulicos, inúmeras pesquisas têm sido desenvolvidas sob condições de laboratório, porém com pouco sucesso na solução do problema antes mencionado.…”