How do entomopathogenic nematodes kill their insect hosts? by Ganpati Jagdale

When the infective juveniles of entomopathogenic nematodes are applied to the soil surface in the fields or thatch layer on glf courses, they start searching for their insect hosts. Once insect larva has been located, the nematode infective juveniles penetrate into the larval body cavity via natural openings such as mouth, anus and spiracles. Infective juveniles of Heterorhabditis nematodes can also enter through the intersegmental membranes of the grub cuticle. Once in the body cavity, infective juveniles release symbiotic bacteria (Xenorhabdus spp. for Steinernematidae and Photorhabdus spp. for Heterorhabditidae) from their gut in insect blood. In the blood, multiplying nematode-bacterium complex causes septicemia and kill their insect host usually within 48 h after infection. Nematodes feed on multiplying bacteria, mature into adults, reproduce and then emerge as infective juveniles from the host cadaver to seek new larvae in the soil.

Control of Black Vine Weevils with Insect Parasitic Nematodes by Ganpati Jagdale

Black vine weevil, Otiorhynchus sulcatus is a common insect pest of over 150 plant species that grown in the greenhouses and nurseries. Some of the plant species damaged by black vine weevils include Azalea, Cyclamen, Euonymus, Fuxia, Rosa, Rhododendron and Taxus. Grubs (Larvae) of these weevils generally girdle the main stem, and feed and damage roots leading to nutrient deficiencies. Adults feed on leaves and flowers by notching their edges thus reducing aesthetic value of plants.

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