Synergistic pesticidal compositions

DETAILED DESCRIPTION OF THE INVENTION The fatty acids used according to the subject invention can be unsubstituted, or substituted, saturated, or unsaturated, fatty acids (or their salts), of about C7 to about C20.
Specifically exemplified are fatty acids of length C15 to C20, as typified by, but not limited to, oleic acid and metal salts of these acids.
The fatty acid component of the subject invention may be a single fatty acid or salt, or a mixture of two or more fatty acids or salts thereof.
Fatty acids, or their salts, which can be used according to the subject invention can be fatty acids, such as oleic acid, which are known to have pesticidal activity.
When used according to the subject invention, these fatty acids, or their salts, can be used in approximately the same concentrations suggested by prior practice, however, by combining these accepted concentrations with a reduced concentration of an avermectin compound, an enhanced pesticidal activity is observed compared to the avermectin compound alone at a standard concentration.
Standard concentrations of fatty acids and avermectins are well known to those skilled in the art.
For example, the avermectin compounds can be employed in the synergistic combination at concentrations of from 0.
03 to 8 parts per million (ppm).
Preferably, from 0.
25 to 3 ppm are employed and, most preferably, from 1 to 3 ppm are employed in dilute solutions for optimum field control of the mite population.
A variety of different avermectins or related compounds can be used alone or in combination according to the subject invention.
Ivermectin may also be used according to the subject invention, as may the milbemycins.
For brevity, the term "avermectin" is used herein to refer to all the avermectins and their derivatives as well as related compounds such as the milbemycins and the ivermectins.
"Derivatives" refer to chemical modifications of the avermectins or milbemycins which are well known and available to those skilled in this art.
Such derivatives are described, for example, in U