IPM Packages for Crops

Stink bug, Johnny N. Dell, Bugwood.org

White-backed planthopper [ Sogatella furcifera , (Homoptera: Delphacidae)] This pest causes ‘hopper-burn.’ Outbreaks are reported in Asia. Bionomics and symptoms resemble brown planthopper. Nilaparvata lugens eggs are parasitized by Anagrus optabilis , Paracentrobia andoi , and Tetrastichus formosanus (Hymenop- tera). Mirid bug Cyrtorhinus lividipennis (Miridae) and predatory mite Amblyseius sp. (Parasitiformes) prey on the eggs. Nymphs and adults of N. lugens are parasitized by Elenchus japonicus (Strep- siptera), Echthrodelphax bicolor (Hy- menoptera), and nematode Hexamermis sp. Fungal pathogen Beauveria bassiana infects them. This pest does not transmit diseases. Leaf folders [ Cnaphalocrocis medinalis, Marasmia pat- nalis and Marasmia exigua (Lepidoptera: Crambidae)] Leaf folders are especially in areas of high nitrogen fertilizer use. Larvae fold leaves longitudinally and fasten leaf margins with stitches of silken threads. Larvae feed by scraping green mesophyll from within folded leaves. Feeding greatly reduces the photosynthetic ability of infested rice plants and heavily infested leaves dry up and appear scorched. Damaged leaves serve as entry points for fungal and bacterial infections. Several species of Diptera (e.g., Megaselia spp. and Argyro- phylax spp.), Hymenoptera ( Goniozus spp., Trichogramma spp., Apanteles spp., and Bracon spp.), Coleoptera ( Chlaenius spp. and Coccinella spp.), Orthoptera ( Anax- ipha spp. and Metioche spp.), Araneae ( Argiope spp., Pardosa spp., and Tetrag- natha spp.), and nematode ( Agamermis spp.) have been reported as parasitoids and predators in Asia. Microbial insecticide Bacillus thuringiensis is effective against larvae.

Case worm [ Nymphula depunctalis (Lepidoptera: Pyralidae)] This pest is a problem in lowland at the vegetative stage of rice. Due to its semi-aquatic mode, it can cause severe damage in paddy fields with standing water. Infestation is more severe in dwarf, compact, heavy tillering, and high-yielding varieties and late maturing rice crop. Lar- vae feed on tender leaves and make cases as they grow. Damage is caused by larvae feeding and cutting off the leaf and cre - ating a ladder-like appearance on leaves. Damaged plants become stunted and produce fewer tillers and smaller panicles, resulting in delayed maturity. Trichogram- ma japonicum, T. chilonis , and T. minutum (Hymenoptera) are egg parasitoids of rice caseworm. Predators such as spiders, birds, and adult dragonflies/damselflies are dom - inant natural predators of caseworm adults, while aquatic beetle larvae, aquatic bug nymphs and adults, and ants feed on caseworm larvae and snails feed on caseworm eggs.

Stink bug [ Nezara viridula (Hemiptera: Pentatomi- dae)] Both nymphs and adults cause damage but adults are particularly damaging. Although they feed on other parts of the rice plant, they prefer grains at the milk stage and even ripening grain. Diffused brown spots caused by the exudation of the sap mark points of insertion of mouthparts. In severe cases of infestation, most grains in a field are sucked empty. Damage during the dough stage causes discoloration of mature grain and causes weakness in the kernel. Such rice has lower milling quality or is pecky rice of inferior grade. Predators such as grasshopper, Conocephalus longipennis (Orthoptera) and assassin bug Nabis stenoferus (Hemiptera) feed on this pest. Trissolcus basalis (Hymenoptera) is used in several countries to manage this pest. Beauveria bassiana also infects this pest.