Entomopathogenic Nematodes (EPNs) скачать в хорошем качестве

Entomopathogenic Nematodes (EPNs)

Entomopathogenic Nematodes (EPNs) EPNs are beneficial nematodes parasitizing insect pests that are being effectively used as biocontrol agents against a wide variety of crop pests. They have a broad host range and can search the target insect in soil, plant surface, and that is partly embedded in plant tissues. Several species of armyworms, cutworms, and earworms that include Agrotis spp., Spodoptera frugiperda, S. exigua, and S. litorallis are highly susceptible to EPN. Genus Steinernema has ambush or sits and waits for host-finding strategy and effective against highly mobile, surface-dwelling insect-pests. The genus Heterorhbditis is highly mobile with cruiser foraging strategy able to hunt for their prey several inches below the soil surface. They ensure a quick kill of the target insect through the release of associated symbiotic bacteria. EPNs will remain active until all the host is killed completely and they undergo resting till the new hosts are found resulting in the recycling of the control. EPNs have target specific action and act only on insects and are safe to animals, human beings, and the environment. EPNs are exempted from registration requirements as they are safe to the environment and non- target organisms. Spodoptera frugiperda which is an important pest of maize, sorghum, cotton, and soybean is susceptible to H. megidis (Jaime Molina Ochoa et al., 2003). Spraying of nematodes on corn ears caused up to 71% infection of S. frugiperda. Sarav et al., 2008 tested the pathogenicity of a local isolate of Steinernema carpocapsae against 3rd, 4th, and 5th instar larvae of Spodoptera litura. Cent percent of mortality was obtained after 96 hrs in all instars. Umamaheswari et al., 2006 reported Heterorhabditis indica 5x109 IJ/ha is effective against Spodoptera litura in black gram Vigna mungo. EPNs formulated as dust, sprays, capsules, and granules, etc. can be used for foliar application, soil application, broadcasting, spray, drip Irrigation, or soil drench but optimum moisture of 30% of field capacity and optimum temperature of 25-30 ℃ are required to apply EPNs in the field. EPNs are also formulated in different ways by using vermiculite, alginate gels, micronized vermiculite, and polyurethane sponge. They are used directly as host cadavers or along with baits. Formulated EPNs can be stored for 2 to 7 months depending on the nematode species and storage media and conditions. V. Viruses for Pest Management