Plant nematodes are microscopic unsegmented roundworms (Photo 1) that cause severe damage to many plant species. A handful soil may contain several different species of plant nematodes including root-knot (Meloidogyne spp.), Sting (Belonolaimus spp.), lance (Hoplolaimus spp.), root- lesion (Pratylenchus spp.), ring (Mesocriconema spp.), stubby-root (Paratrichodorus spp.), spiral (Helicotylenchus spp.), dagger (Xiphinema spp.) and cyst (Heterodera spp.) nematodes (Photo 1). Of these nematode species, root- nematode is considered the most economically important pests of many plant species including field crops (cotton, peanut, soybean, corn etc) and vegetables (tomato, peppers, cucumbers, eggplants etc).
Predatory mites, Stratiolaelaps scimitus (Hypoaspis miles) are currently used for the organic control of fungus gnats (Bradysia spp.).
Whiteflies are one of the most damaging insect pests of many greenhouse and field vegetables. The beneficial nematodes like Steinernema feltiae can be used for the effective killing of whiteflies.
Japanese beetles (Popillia japonica) are one of the most damaging insect pests of many agricultural and horticultural crops, ornamental plants and turfgrasses. Larvae of Japanese beetles are also called as grubs that mainly damage plant roots whereas their adults damage only aboveground plant parts like flowers, fruits, leaves and twigs.
Volatile organic compounds (VOCs) with nematicidal activities are naturally occurring chemicals generally found in and easily emitted as vapors and gases from many living organisms like bacteria and fungi, and plants.
The fall armyworm, Spodoptera frugiperda is one of the most economically important pests of different plant species including corn, sorghum, forage, and turf grasses. Although fall armyworm larvae actively damage crops throughout the United States during growing season, they generally die when harsh winter begins in northern, central and eastern United States. Then question arises how they could re-infest fields and cause damage to the crops grown in these areas during spring and summer again.
Six newly described species including Steinernema beitlechemi, Steinernema fabii, Steinernema innovation, Steinernema jeffreyense, Steinernema sacchari and Steinernema tophus have been reported from South Africa.
Plant-parasitic nematodes including root-knot nematodes are the most damaging pest of many organically grown vegetables like beans, carrots, cucumbers, eggplants, melons, okra, peas, peppers, potatoes, squash and tomatoes.
A new species of entomopathogenic bacteria was isolated from Steinernema aciari nematode is now called as Xenorhabdus ishibashii.
Four beneficial nematodes including Heterorhabditis bacteriophora, Steinernema feltiae, Steinernema intermedium and Steinernema kraussei have been reported from Portugal.