Effect of extract of of Mentha piperita, Salvia officinalis, Glycyrrhiza glabra and Crocus sativus on hemocytes and phenoloxidase avtivity in larvae of Plodia interpuncetlla (Lepidoptera: Pyralidae)

Hemolymph of insects is their last defense barrier against foreign factors such as poison particles, pollutants, fungal and bacterial spores and plant metabolites. As the main pillar of physiological defense, hemocytes circulate in the hemolymph and react to stress by changing their number in the early stages. In this research, the effect of the aqueous extract of Mentha piperita, Salvia officinalis, Glycyrrhiza glabra and Crocus sativus on the immune system of Plodia interpuncetlla Hubner (Lepidoptera: Pyralidae) was investigated. Fourth instar larvae were treated with aqueous extracts of plants in concentrations of 10, 6 and 20%. hemocyte density and phenol oxidase activity were measured and recorded in two time periods of 24 and 48 hours. The results showed that the effect of different extracts on the total number of cells, plasmotocytes and granulocytes was significant compared to the control and increased with the increase in the concentration of the extracts in all treatments and at both test times. The total number of cells in the treatment of S. officinalis with a concentration of 6% after 48 hours and M. piperita with concentrations of 20% and 10% increased the most compared to the control. The number of granulocytes under the treatment of S. officinalis with a concentration of 6% after 48 hours showed the greatest increase compared to the control group. plasmotocytes also increased significantly under the effect of M. piperita treatment with concentrations of 10% and 20% after 24 hours and 20% concentration after 48 hours compared to the control. According to the evaluations, the 20% concentration of S. officinalis showed the highest increase in phenol oxidase activity compared to the control and other treatments. The obtained results confirmed the response of the P. interpunctella immune system to the introduction of plant extracts into the hemolymph, which was associated with significant changes in cell density and phenol oxidase enzyme activity. .