The Effects of Natural Biopesticide from Mirabilis jalapa toward the Immune System of Spodoptera litura

Biological control provides a safer alternative to reduce the population of agricultural pest. Mirabilis jalapa is one of biopesticides containing chemical substances that have a feeding deterrent property against Spodoptera litura as folifagus insect pest. This study aimed to analyze the humoral and cellular immunes responses of S. litura after exposure to biopesticide extracted from M. jalapa. The measured indicator immune responses were activity of hemocyte, lectin, phenoloxidase (PO), and phagocytic activity. The results showed that the average total hemocyte was different significantly depending on the treatment. Exposure to 0.1% and 0.2% (w/v) of M. jalapa extract increased the total number of hemocytes as much as 38.08% and 64.15%, respectively. Lectin was quickly formed at 0.1% and 0.2% (w/v) concentrations. The amount of PO enzymes was significantly different at sublethal concentrations compared with control samples (P < 0.05). The highest increase in PO activity occurred at 2 h post-treatment and at M. jalapa extract concentrations of 0.2% (592.33 IU/mg) and 0.1% (521.33 IU/mg), whereas the highest concentration of the extract (0.8% w/v) caused a decrease in lectin and PO activities. In terms of phagocytic activity, the proportion of phagocytosis cells were 47.62% in control group, and decreased significanlty in both concentrations exposure.