Abstract
The synthesis of cuticular and hemolymph lipids in the scorpion Paruroctonus mesaensis, was examined using radiolabeled acetate and palmitic acid. Incorporation of 1β^14^Cβacetate into cuticular lipids was very low (0.03β0.13% of injected label), with the hydrocarbons exhibiting only trace (CPM's not significantly higher than background) radioactivity after 24 hours. Cuticular alcohols had the highest incorporation (ca. 80%) followed by free fatty acids and triglycerides. Hemolymph lipids also showed poor incorporation of labeled acetate (0.01%) and little activity in the hydrocarbon fraction. Incorporation of 1β^14^Cβpalmitic acid into cuticular lipids (0.86β1.21%) and hemolymph lipids (0.62β1.00%) was slightly higher, but still well below incorporation values observed for insects. The majority of the label appeared in the free fatty acids; hydrocarbons continued to show only trace radioactivity. Except for differences in the relative amounts of specific components, cuticular and hemolymph hydrocarbons were similar in composition. These results suggest that hydrocarbon biosynthesis in adult scorpions is very low during the intermoult period or that other compounds are preferred precursors.