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The relative toxicities of insecticides to earthworms of the Pheretima group (Oligochaeta)
- Mostert, Magdel A., Schoeman, At S., Merwe, Mac van der
- Pest management science 2002 v.58 no.5 pp. 446-450
- Pheretima, application rate, carbaryl, chlorpyrifos, cyfluthrin, earthworms, fipronil, imidacloprid, lethal concentration 50, pests, soil, toxicity, turf grasses
- An artificial soil test was used to determine the LC50 values of carbaryl, chlorpyrifos, imidacloprid, cyfluthrin and fipronil against earthworms of the Pheretima group. For a 24-h interval, carbaryl was the most toxic to earthworms (LC50 = 77 mg kg−1), followed by imidacloprid (155 mg kg−1), cyfluthrin (351 mg kg−1), chlorpyrifos (390 mg kg−1) and fipronil (>8550 mg kg−1) as the least toxic. For the 48-h and 7-day intervals, imidacloprid was the most toxic to earthworms (LC50 = 5 mg kg−1 and 3 mg kg−1 respectively), followed by carbaryl (16 mg kg−1; 9 mg kg−1), cyfluthrin (128 mg kg−1; 110 mg kg−1), chlorpyrifos (330 mg kg−1; 180 mg kg−1) and the least toxic was fipronil (>8550 mg kg−1 both intervals). The surface application rates required to achieve these values are compared with the rates recommended for the control of turfgrass pests.