Effect of Chitin Synthesis Inhibitor, Flufenoxuron on Haemocytes of Spodoptera Mauritia (Boisd). (Lepidoptera: Noctuidae)
Larvae of Spodoptera mauritia (Lepidoptera: Noctuidae) were treated with 2.5 ppm and 5 ppm flufenoxuron and their haemogram were investigated after 24 and 48 hours of post- treatment. The haemogram of Spodoptera mauritia comprised eight distinct classes of haemocytes. They are Plasmatocytes, Granulocytes, Prohaemocytes, Spherulocytes, Adipohaemocytes, Oenocytoids, Vermicytes and Podocytes. In the normal day1 sixth instar larvae, THC populations of 1.3860±3.1199 cells/mm3 and in day2 larvae, 1.2540±4.1548 cells/mm3 in haemolymph were recorded. The percentage of DHC number of plasmatocytes was the highest 73.50±4.062, compared to untreated larvae (1.3860±3.1199 cell/mm3 of haemolymph). THC steeped down to 1.2320±3.3122 cells/mm3 of haemolymph and 1.000±3.5925 cell/mm3 of haemolymph at 24 hrs after treatment of the flufenoxuron with 2.5 ppm and 5 ppm, respectively. The haemocytes decreased during 24 hrs and 48 hrs after the treatment with 2.5 ppm and 5 ppm of flufenoxuron, compared with the control. Various abnormalities were evidenced in the haemocyte after 24 and 48 hours, post treatments of flufenoxuron (2.5 ppm and 5 ppm) on the sixth instar larvae of Spodoptera mauritia. Major changes were observed in granulocytes and plasmatocytes. These data imply that these two concentrations (2.5 ppm & 5 ppm) of flufenoxuron could strongly interfere with the differentiation of haemocytes and thereby decrease the capability of larval immune defense.