Studies on the Entomopathogenic Nematodes in Sindh

Abstract

Entomopatthogenic nematodes have been recognized as one of the most effective biological control agents for the control of insect’s pests which are causing serious damage to our agricultural crops. So far now no work has been conducted on this aspect in Pakistan. Under this project entomopathogenic nematodes belongings to steinernematid and heterorhabditid group, were extracted from soil samples collected from various field of Pakistan, using Galleria mellonella larvae as bait. Nematoders were recovered from infested larvae through white trap technique. During this period 915 soil samples were collected from 35 different localities in Karachi, Hyderabad, thatta, badin ,and mirpurkhas of Sindh and sonmiyani beach, sanghoraa sea n shore of Baluchistan, Pakistan. Out of 915 soil samples EPN were detected in 113 sampling sites which include 90 isolates of Heterorhabditis and 23 isolates of steinernema. These entomopathogenic nematodes were recovered only from sandy loam soil showing 100% recovery while EPN could not be detected from clay loam soil. Under the present detail taxonomic studies Heterorhabditis indica poinar et al (1992), found widely distributed in different habits of Sindh, Pakistan is red scribed, while two undesired species of the genus steinernema were recovered. Specimens of S. asiatica n.sp. Were collected from the soil of coconut plantation, grasses and ornamental plants in Malir area and Gulshan e Maymar Karachi, Sindh Pakistan. Second new steinemema species is described hereas S. pakistanensis (BS266) n.sp. was collected from soil of grasses, ornamental plants and vegetables in Sindh and Baluchistan provinces of Pakistan. Pathogenicity of an entomopathogenic nematode steinernema pakistanensis (BS266) n.sp. was tested under laboratory condition against six important tropical Lepidoptera species viz., American bollworm of cotton against six important tropical Lepidoptera species viz., American bollworm of cotton ( Heliothis armigera) spotted bollworm of cotton ( Earias insulana and E. vittella) pink bollworm of cotton (pectinophora ) lemon butterfly ( papillio demoleus) brinjal fruit borer (Leucinodes orbondalis ) and pod borer ( Etiella zinckenella) as well as against one coleopteran apecies, the white grub ( holotrichia consanguinea) and two unidentified species of insects. Steinernema pakistanensis (BS266) n.sp was found most effective giving 100% morality after 12 hr. exposure with approximately important inse3ct species viz., American bollworm of cotton ( Heliothis armigera), spotted bollworm of cotton ( Earias insulana and E. Vittella), and pink bollworm of cotton (pectinophora gossypiella ) were reared in laboratory on artificial diet for further investigation.