Efficiency of parasitoid, Dinarmus vagabundus (Timberlake) in inhibiting the multiplication of stored grain pest, Callosobruchus maculatus (F.) in stored mungbeans

The searching ability of parasitoid, Dinarmus vagabundus and its effectiveness in inhibiting the multiplication of its host, Callosobruchus maculatus (F.) in storage were studied under laboratory conditions. The female parasitoid located the host larvae kept at the depth of 110 cm in bulk mungbean grains and parasitised them. The upward movement of female parasitoid was better compared to downward movement in storage structure. The effectiveness of parasitoid for controlling bruchid multiplication in storage was studied in artificially infested mungbean sample size of 200 g. The samples were infested with different host stages at infestation levels of 1 and 5%. Release of 10 female parasitoids was found to suppress the multiplication of C. maculatus at 1% infestation level. However, at 5% infestation level, release of 40 female parasitoids was needed to achieve similar results. Single release of parasitoids was sufficient to control the bruchids if grains were infested with single stages of host larvae, however, more than 2 releases were needed if the grains were infested with different stages of C. maculatus.