5-O-demethylavermectin A1a (i) mixture with 5-O-demethyl-25-de(1-methylpropyl)-25-(1-methylethyl)avermectin A1a (ii) 

Colourless to pale yellow crystals.

161.8-169.4 °C

<3.7 ×10-3 mPa (25 °C)

1.18 (22 °C)

In water 7-10 mg/l (20 ºC). In toluene 350, acetone 100, isopropanol 70, chloroform 25, ethanol 20, methanol 19.5, n-butanol 10, cyclohexane 6 (all in g/l, 21 ºC).

Stable to hydrolysis in aqueous solutions at pH 5, 7, and 9 (25 ºC). Sensitive to stronger acid and base. U.V. irradiation causes conversion first to the 8,9-Z- isomer, then to unidentified decomposition products.

2.7 ×10-3 Pa m3 mol-1 (25 °C)

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. 

Insecticide and acaricide with contact and stomach action. Has limited plant systemic activity, but exhibits translaminar movement. 

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.

May be phytotoxic to pome fruit when mixed with captan.  

Not compatible with captan.

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. 

OralAcute oral LD50 (in sesame oil) for rats 10, mice 13.6 mg/kg; (in water) for rats 221 mg/kg. 

Acute percutaneous LD50 for rabbits >2000 mg/kg. Mild eye irritant; non-irritating to skin (rabbits). 

(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). OtherNon-mutagenic in the Ames test. 

EPA (formulation) IV 

Acute oral LD50 for mallard ducks 84.6, bobwhite quail >2000 mg/kg. 

LC50 (96 h) for rainbow trout 3.2, bluegill sunfish 9.6 mg/l. 

EC50 (48 h) 0.34 ppb. 

(72 h) for Pseudokirchneriella subcapitata >100 mg/l. 

LC50 (28 d) for earthworms 28 mg/kg soil. 

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. 

Rapidly eliminated (80-100% in 96 h), mainly via faeces; urinary excretion was 0.5-1.4%.

Binds tightly to soil, with rapid degradation by soil micro-organisms. No bioaccumulation.