Evaluation of chlorpyrifos and fenchlorphos for control of major insect pests of pastures in Australia
In field experiments sprays of chlorpyrifos and fenchlorphos were compared with standard recommendations for control of five pasture pests. Field experiments were done on Halotydeus destructor (Tucker) in New South Wales and Victoria in 1970, Sminthurus viridis (L.) in South Australia in 1970, Aphodius tasmaniae Hope in South Australia in 1970 and 1971 and Oncopera rufobrunnea Tindale and O. alboguttata Tindale in New South Wales in 1970. Against H. destructor, chlorphyrifos at 35 g ha-1 in one experiment, and at 70 g ha-1 in another, was as effective as the standard phosmet treatment. Fenchlorphos at 210 g ha-1 reduced H. destructor in both experiments less effectively than phosmet. Chlorpyrifos at 17.5 g ha-1 controlled S. viridis as effectively as phosmet. A. tasmaniae larvae were controlled by chlorpyrifos at 420 g ha-1 as effectively as the standard lindane treatment. Fenchlorphos at 630 g ha-1 did not reduce A. tasmaniae larvae numbers below that of the control. Chlorpyrifos at 21 0 g ha-1 and fenchlorphos at 140 g ha-1 controlled O. rufobrunnea and O. alboguttata larvae as effectively as the standard chlorfenvinphos treatment.