The rice swarming caterpillar, Spodoptera mauritia
, is one of the major paddy pest, which causes serious loss of rice crops. Several problems associated with the use of conventional insecticides have strongly demonstrated the need for applying alternative safe compounds such as insect growth regulators (IGRs). The present study was carried out to investigate the effect of ecdysone agonist, Chromafenozide on the larval hemogram of S. mauritia
. The fifth instar (penultimate) day 0 larvae were treated with three known concentrations of Chromofenozide(0.5µM, 1µM,2µM ) and they were observed at 24 hour intervals. THC was found to first increase and then decrease at lower concentrations, while at higher concentration, it was found gradually decreasing. The haemogram evidenced after the treatment with lower concentrations showed a remarkable decrease in PLs, OEs, PRs ADs, POs, and VEs at 24 and48 hours, while GRs and SPs exhibited an increase than the control. At higher concentrations, THC values of haemocytes were found to be decreased after 24 and 48 hours as when compared to control. Also, the percentage of all the haemocytes decreased after 72 hours of treatment with three concentrations, as when compared with the control. Administrations of these three concentrations resulted in various cellular abnormalities. The impact of ecdysone agonist, chromafenozide exhibited a decrease in capability of larval immune defense of S.mauritia
, by altering the hormonal triggers in the treated individuals, causing significant changes both quantitatively and qualitatively in the haemogram obtained.