Department of Zoology, Annamalai University, Annamalai Nagar-608 002, Tamil Nadu (India).
*Present Address: Department of Animal Science, Bharathidasan University, Tiruchirapalli-620 024, Tamil Nadu (India).
The fat body of Periplaneta americano (Linn.) is transparent yellow coloured mass within the coelomic cavity. In control insects, the fat body contains three types of cells, viz, trophocytes, urocytes any mycetocytes. Trophocytes consist of large lipid vacuoles and nuclei. Urocytes store uric acid in the form of fine granules and seem to be involved in excretion. The third, less common type, are mycetocytes. The fat body showed some marked changes in insects injected with sublethal concentration of Pongamia glabra (Vent.) leaf extract (0.05 ml of 5% concentration) through intra-peritoneal membrane. In treated insects, the lipid vacuoles of trophocytes disintegrate. Swollen and irregular shaped nuclei are conspicuous. Mycetocytes decrease in size. Urocytes are mostly disintegrated.
