The relative toxicities of insecticides to earthworms of the Pheretima group (Oligochaeta).
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.
Mostert
Magdel A
MA
Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002, South Africa. mmellet@zoology.up.ac.za
Schoeman
At S
AS
van der Merwe
Mac
M
D000818:Animals; D012721:Carbaryl / Q000008:administration & dosage / Q000633:toxicity; D004390:Chlorpyrifos / Q000008:administration & dosage / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D007093:Imidazoles / Q000008:administration & dosage / Q000633:toxicity; D007306:Insecticides / Q000008:administration & dosage / Q000633:toxicity*; D000073943:Neonicotinoids; D009570:Nitriles; D009574:Nitro Compounds; D009835:Oligochaeta / Q000187:drug effects*; D011720:Pyrazoles / Q000008:administration & dosage / Q000633:toxicity; D011722:Pyrethrins / Q000008:administration & dosage / Q000633:toxicity; D012987:Soil / Q000032:analysis; D013997:Time Factors
D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009570:Nitriles; D009574:Nitro Compounds; D011720:Pyrazoles; D011722:Pyrethrins; D012987:Soil; C082359:imidacloprid; D004390:Chlorpyrifos; C082360:fipronil; D012721:Carbaryl; C052570:cyfluthrin