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

Abstract

The efficacy of bifenthrin (0.5 mg/kg) + piperonyl butoxide (7 mg/kg) + chlorpyrifosmethyl (10 mg/kg) against beetle and psocid pests of sorghum was evaluated in silo-scale trials in southeast Queensland, Australia. The pyrethroid bifenthrin was evaluated as a potential new protectant in combination with the organophosphate chlorpyrifos-methyl, which is already registered for control of several insect pests of stored cereals. Sorghum (approximately 200 metric tons) was treated after both the 1999 and 2000 harvests and sampled at intervals to assess treatment efficacy and residue decline during up to 7 mo of storage. Generally, test strains of the beetles Rhyzopertha dominica (F.), Tribolium castaneum (Herbst), Oryzaephilus surinamensis (L), and Cryptolestes ferrugineus (Stephens) were prevented from producing live progeny for up to 7 mo. The treatment failed against one strain of R. dominica known to be resistant to bioresmethrin and organophosphates. Two malathion-resistant strains of O. surinamensis were marginally controlled with 94-100% fewer adult progeny produced. For psocids, no strains of Liposcelis bostrychophila Badonnel, Liposcelis decolor (Pearman), or Liposcelis paeta Pearman produced live progeny, although the control of a field strain of Liposcelis entomophila (Enderlein) was generally poor. Results show that this treatment should protect sorghum for at least 7 mo against most prevalent strains of grain insect in eastern Australia, although control may be limited in areas in which L. entomophila or pyrethroid-resistant R. dominica are present.

Potential of piperonyl butoxide‐synergised pyrethrins against psocids (Psocoptera: Liposcelididae) for stored‐grain protection

“…For example, a rate of 3 mg kg −1 of synergised pyrethrins was enough to achieve population extinction of L. bostrychophila and L. decolor at the end of a 3 month trial, as opposed to 6 mg kg −1 that was required to obtain the same result against L. entomophila and L. paeta. These results confirm earlier observations that L. entomophila and L. paeta are generally more tolerant to grain protectants than L. bostrychophila and L. decolor ,4, 5, 8, 10 with the exception that L. bostrychophila appear to be more tolerant than L. entomophila to natural pyrethrins applied to concrete surfaces 16. The experiments on time to endpoint mortality in adults demonstrated that 6 mg kg −1 of synergised pyrethrins can produce complete mortality in all Liposcelis spp.…”

“…A series of studies has implicated either development of resistance or tolerance to registered chemical treatments in the emergence of these pests in Australia. In addition to the detection of phosphine resistance in several species,6, 7 some populations of L. entomophila and L. paeta have been demonstrated in laboratory trials to have survived in wheat treated with organophosphates (fenitrothion, chlorpyrifos‐methyl and pirimiphos‐methyl), pyrethroids (deltamethrin, bioresmethrin and bifenthrin), the carbamate carbaryl and the insect growth regulator methoprene at registered application rates 4, 8. More recently, two newly developed materials, the bacterium‐derived spinosad and the neonicotinoid imidacloprid, failed to control the four pest species of Liposcelis 9, 10.…”

Potential of imidacloprid to control four species of psocids (Psocoptera: Liposcelididae) infesting stored grain

“…The most significant result from the this study was that imidacloprid effectively controlled both adults and progeny in all four Liposcelis species at an application rate of 10 mg AI kg −1 . None of the currently registered grain protectants can control all four species,1, 14–18 and neither can spinosad, which is likely to be registered soon 19. We conclude that if registered, imidacloprid has the potential to control four Liposcelis psocid species in Australia and elsewhere in the world where they have developed resistance to organophosphates, insect growth regulators and pyrethroids.…”

“…Moreover, a comprehensive review of psocids3 suggests that one or more of these psocids are established pests of stored commodities in several countries in Asia,4–6 Europe,7–9 Africa10, 11 and the Americas 12, 13. Laboratory studies in Australia have shown that none of the currently registered grain protectants can control all four Liposcelis species 1, 14–18. Similarly, spinosad, which is expected to be registered in Australia, failed to control these psocids 19.…”

Synthesis, insecticidal activity, and phytotoxicity of novel chiral amides

“…The treatments were the 14 synthesized amides and the efficiency standard Bifenthrin® (92.2% w/w. FMC Quimica, Campinas, Brazil) applied at the dose of 44.05 µmol g −1 of insect . Six replicates were performed for each treatment.…”