Abstract
Chromatographic analysis of the fats of 30 species of Insecta and 2 species of Arachnida showed specific differences, and also two characteristics apparently related to existing taxa: a high concentration of myristic acid in fats of Aphidoidea, and a high concentration of palmitoleic acid in Diptera. A possible relationship between the high palmitoleic acid content of the fat of Agria affinis (Fallén) (Diptera: Sarcophagidae) and its lack of requirement for polyunsaturated fatty acids is suggested.