Studies on anti fungal effect of mite alarm pheromone citral part 1 evaluation of anti fungal effect of citral
Okamoto, M.; Matsumoto, K.; Wada, Y.; Nakano, H.
Medical Entomology and Zoology 29(3): 255-260
It was observed that there was no growth of fungi on the food of grain mites but that fungi grew when the mites died. Kuwahara et al. (1975) and Kuwahara (1976) found 2 kinds of alarm pheromones, Citral and Neryl formate, in the grain mites. To study the ecological role of the alarm pheromone, the antifungal effect of the pheromone was investigated. Three methods, the cup method, the gas method and the modified gas method, were employed to observe the antifungal effect of Citral and the hexane extract of Carpoglyphus lactis on Aspergillus fumigatus. To determine whether or not Citral was effective in evaporated gas, the gas method was applied. The growth of A. fumigatus was inhibited and the antifungal effect of Citral was due to the action of the evaporated gas. Lastly, A. fumigatus was inoculated in the center of the plate in a pin point. A paper disc with Citral hexane solution was placed in the center of the lid. The degree of the fungal growth was equal to the diameter of the colony. One milliliter hexane extract of C. lactis had the same potency as 4.8 mg/ml of Citral. Some grain mites eat fungi. The antifungal effect of Citral in the grain mites may also play a role in preventing fungal growth.