Characterization, distribution, catabolism, and synthesis of the fatty acids of the two-spotted spider mite, Tetranychus urticae

Abstract

A method is described that permits limited culture of Tetranychus urticae Koch in a chemically defined diet. The fatty acids of the mite T. urticae consist of normal saturated and monoenoic acids of from 12 to 20 carbon atoms. Polyunsaturated linoleic and linolenic acids are also found. The C 18 series of fatty acids comprise over 80 per cent of the total fatty acids. There is an increase in linolenic and a decrease in palmitic and palmitoleic acids during progression through the protonymphal, deutonymphal, and adult growth stages. The proportions of the other fatty acids remain nearly constant during the growth phases. A higher proportion of stearic and a lower proportion of linolenic acid are contained in the phospholipids than in the neutral lipids. Starvation of the mites leads to a rapid loss of linolenic acid with lesser decreases of the other fatty acids. Palmitic acid is rapidly utilized by starving adult mites in some experiments. Adult mites maintained on a liquid diet containing tritiated acetate incorporate the isotope into saturated monoenoic and polyenoic fatty acids.