【Aim】 This study explored the effect of parasitization by different strains of Tetrastichus brontispae (Tb-On and Tb-Bl strains reared on Octodonta nipae and Brontispa longissima pupae, respectively) on lipid droplets of O. nipae and B. longissima pupae to provide a scientific basis for understanding the effect of parasitization on the lipid metabolism of two beetles. 【Method】 The morphology of lipid droplets from two strains of T. brontispae larvae and fat body tissues from host beetle pupae parasitized by T. brontispae was analyzed using Oil red O staining. 【Result】 The lipid droplets in two strains of wasp larvae had a similar configuration and distribution during development in the egg stage at 48, 72, and 96 h. Few lipid droplets on the head and cuticle of wasp larvae were found at the early stage of development, thereafter the number of lipid droplets in larvae increased gradually until they filled the hemocoel. There was no significant difference between the lipid droplets from the same host pupa post-parasitized by different strains of T. brontispae. However, a significant difference was presented in the impact on lipid droplets of different host pupae post-parasitized by the same strain of T. brontispae. The lipid droplets in O. nipae pupae started to be decomposed at 24 h post-parasitization of T. brontispae, and their Oil red O relative area and optical density value increased and decreased, respectively. The lipid droplets in B. longissima pupae started to be decomposed at 48 h post-parasitization by T. brontispae. This demonstrated that the Oil red O relative area and integral optical density of the two hosts decreased during the development of the wasp larvae. Thereafter, the lipid droplets became paler or even disappeared. 【Conclusion】 There was no significant difference in the configuration and distribution of lipid droplets in different strains of T. brontispae during their development. After parasitization of the same strain of T. brontispae, the fat body in O. nipae pupae was decomposed earlier than that in B. longissima pupae. The lysed lipid droplets likely provide lipid nutrients for the development of T. brontispae larvae.