Beans, Grains & Cereals

Colourless Insecticide Pesticide Biopesticide Abamectin 95%TC CAS 71751-41-2

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COMMERCIALISATION

Production Isolated from fermentation of Streptomyces avermitilis, a naturally occuring soil Actinomycete. History Anthelmintic and acaricidal activity of a group of chemically related compounds, the avermectins, reported by I. Putter et al. (Experientia, 1981, 37, 963). A mixture of two of these, avermectin B1a (i) and avermectin B1b (ii) introduced in 1985 as an acaricide and insecticide by Merck Sharp & Dohme Agvet (now Syngenta AG). Manufacturers Jingma; Sharda; Sinon; Syngenta; Tide

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APPLICATIONS

Biochemistry Acts by stimulating the release of g-aminobutyric acid, an inhibitory neurotransmitter, thus causing paralysis. See M. J. Turner & J. M. Schaeffer in Ivermectin and Abamectin, W. C. Cambell ed., Springer-Verlag, New York (1989) p. 73. Mode of action Insecticide and acaricide with contact and stomach action. Has limited plant systemic activity, but exhibits translaminar movement. Uses Control of motile stages of mites, leaf miners, suckers, Colorado beetles, etc. on ornamentals, cotton, citrus fruit, pome fruit, nut crops, vegetables, potatoes, and other crops. Application rates are 5.6 to 28 g/ha for mite control, 11 to 22 g/ha for control of leaf miners. Also used for control of fire ants. Phytotoxicity May be phytotoxic to pome fruit when mixed with captan. Formulation types EC. Compatibility Not compatible with captan. Selected products: & acute;Agrimec& acute; (Syngenta); & acute;Dynamec& acute; (Syngenta); & acute;Vertimec& acute; (Syngenta); & acute;Abacide& acute; (Mauget); & acute;Abamex& acute; (Vapco); & acute;Biok& acute; (Cequisa); & acute;Gilmectin& acute; (Gilmore); & acute;Romectin& acute; (Rotam); & acute;Satin& acute; (Sanonda); & acute;Timectin& acute; (Tide); & acute;Vibamec& acute; (Vipesco)

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MAMMALIAN TOXICOLOGY

Reviews FAO/WHO 74, 80, 82 (see part 2 of the Bibliography). G. Lankas & L. R. Gordon in Toxicology in Ivermectin and Abamectin, W. C. Campbell ed., Springer-Verlag (1989) pp. 89-112. Oral Acute oral LD50 (in sesame oil) for rats 10, mice 13.6 mg/kg; (in water) for rats 221 mg/kg. Skin and eye Acute percutaneous LD50 for rabbits >2000 mg/kg. Mild eye irritant; non-irritating to skin (rabbits). ADI (JMPR) 0.002 mg/kg b.w. [1997] (for sum of abamectin and 8,9-Z- isomer); 0.001 mg/kg b.w. [1995] (for residues not containing D-8,9-isomer). Other Non-mutagenic in the Ames test. Toxicity class EPA (formulation) IV

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ECOTOXICOLOGY

Birds Acute oral LD50 for mallard ducks 84.6, bobwhite quail >2000 mg/kg. Fish LC50 (96 h) for rainbow trout 3.2, bluegill sunfish 9.6 mg/l. Daphnia EC50 (48 h) 0.34 ppb. Algae (72 h) for Pseudokirchneriella subcapitata >100 mg/l. Other aquatic spp. LC50 (96 h) for pink shrimp (Panaeus duorarum) 1.6, blue crab (Callinectes sapidus) 153 ppb. Bees Toxic to bees. Worms LC50 (28 d) for earthworms 28 mg/kg soil.

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ENVIRONMENTAL FATE

Animals Rapidly eliminated (80-100% in 96 h), mainly via faeces; urinary excretion was 0.5-1.4%. Plants Degradation/metabolism in each of three different plants is similar and occurs predominantly by photolysis on the plant surfaces. The definition of the residues is thus expressed as the combined residues of avermectin B1 and its 8,9-Z-avermectin B1 photoisomer. Soil/Environment Binds tightly to soil, with rapid degradation by soil micro-organisms. No bioaccumulation.