none In this study, the fatty acid composition of eggs, and all larval and pupal developmental stages, and male and female adults of hymenopterous endoparasitoid, Pimpla turionellae L., reared on Galleria mellonella L. under laboratory conditions, were analysed separately by gas chromatographic methods. Quantitative analysis of the samples showed oleic, palmitic, linoleic and linolenic acids constituted the major part of the fatty acid compositions. Stearic hexadecadienoic, palmitoleic, myristic, myristoleic and lauric acids were, however, found in rather small percentages. Total fatty acid compositions of P. turionellae showed similar values to that of its host. Changes in the mean percent values of total saturated, unsaturated and polyunsaturated fatty acids of P. turionellae could be explained by varying requirements of energy for growth and development, egg production and flying in different stages.