Dietary Toxicity Tests with Mallards, Simulating Residue Decline of Chlorpyrifos and Avoidance of Treated Food

    Published: Jan 1979

      Format Pages Price  
    PDF (144K) 9 $25   ADD TO CART
    Complete Source PDF (1.5M) 9 $55   ADD TO CART


    Dietary 11-day toxicant feeding tests were used to determine the effects of chlorpyrifos on repellency, lethality, food intake, and growth responses by mallards. Avoidance of food was noted at all concentrations tested (56 to 1124 ppm) with consequential decreases in weight growth. When an option between treated and untreated food was available, very little chlorpyrifos was consumed. Tests with dietary concentrations of chlorpyrifos simulating approximately the daily five-day half-life residue rate of decline on foliage treated with chlorpyrifos were compared with tests run under standard conditions where dietary concentrations were held constant throughout the 11-day toxicant feeding period. Initial concentrations resulting in LC50's for these tests were 644 and 357 ppm, respectively. These comparisons indicate that results from standard LC50 tests have a considerable added safety factor for compounds with a short residue half-life.


    residue, half-life, repellency, chlorpyrifos, simulation, toxicity, birds

    Author Information:

    Kenaga, EE
    Research Scientist, The Dow Chemical Company, Midland, Mich

    Fink, RJ
    Wildlife toxicologists, Wildlife International, Ltd., Easton, Md

    Beavers, JB
    Wildlife toxicologists, Wildlife International, Ltd., Easton, Md

    Committee/Subcommittee: E35.26

    DOI: 10.1520/STP35988S

    CrossRef ASTM International is a member of CrossRef.