Large amounts of nutrients are stored in insect oocytes, during oogenesis, as resources for embryogenesis. Lipids are synthesized by extra ovarian organs, like fat body, and sequestered by developing ovaries. In this study, we analyzed the formation of lipid reserves during oocyte growth, and their utilization during embryogenesis. Oocytes were isolated from mated and virgin females ovaries and three stages of development were chosen according to oocyte length: 1.0 (pre-vitellogenic), 1.5 (vitellogenic) and 2.0 mm (mature). Laid eggs, at different days after oviposition, were collected. Lipids were extracted and analyzed by thin layer chromatography (TLC) followed by densitometry. Our results showed that oocytes accumulated triacylglycerol (TG) during oogenesis and this content decreased during embryo development in fertilized eggs (from 17.6 + 2.3 to 10.0 + 1.3 μg/egg). In contrast, the amount of TG remained constant in unfertilized eggs. At 7^th day part of the TG content was found in the embryo (7.4 + 0.9 μg/embryo), and this amount was found in the nymph soon after hatching (7.4 + 0.22 μg/nymph). TG was the major neutral lipid during whole embryogenesis in both types of eggs and in embryo, but free fatty acids, diacylglycerol (DG) and cholesterol were also detected. The TG content present in the newly hatched nymphs decresead during the initial days of life. So, TG stores that are accumulated during oogenesis inside oocytes are consumed during embryogenesis, probably to fuel development of embryos, and also provide nutrients for the newly hatched nymphs. To characterize lipid transport to ovary, R. prolixus females were injected with radioactive fatty acid (³H-palmitic acid) and hemolymph was collected after two hours. Lipophorin (Lp) was then purified from radioactive hemolymph by KBr ultracentrifugation gradient. This ³H-Lp was predominantly labeled in DG and it was injected in non radioactive females. Ovaries and hemolymph were collected at different times. ³H-Lp transfered DG to ovaries when females were kept at 28^o C, but not at 0^o C. When Lp was labeled with radioactive fatty acids, and not DG, it was able to transfer them to ovaries too. Radioactive DG delivered by ³H-Lp to oocytes were important to accumulation of lipid stores, as radioactive lipids, especially TG, were found inside oocytes and laid eggs.