Rice water weevil

About 1000 pg/L (as judged by 280 g/ha in rice field water 10 cm deep) Significant reductions in immature populations of the rice water weevil (Lissorhopterus oryzophilus) 4-5 days after rice emergence in a continuously flooded field 12... 

Smith, K.A., A.A. Grigarick, and M.J. Oraze. 1988. Field evaluations of diflubenzuron and triflumuron for control of the rice water weevil in California rice fields. Jour. Agricul. Entomol. 5 121-126. 

Rice Water Weevil (Lissorhoptrus simplex). Isely and Schwardt (16) who worked with this insect from 1930 to 1933, inclusive, state, The rice water weevil is the most important insect pest of rice in Arkansas. It seems likely that this statement also applies to most of the other rice-producing areas of the southern states. Although the adult weevils feed to a considerable extent on rice leaves, the principal injury is caused by the larvae feeding on the rice roots. Under conditions of heavy infestations practically all the roots are destroyed approximately 4 to 5 weeks from the time of the first flooding of the fields. Normally, even under such conditions, the rice is not killed and when the larvae have matured and ceased feeding, the plants produce a new set of roots and will still produce a crop. The severe setback given the plants during this period naturally results in a marked reduction in yield. 

When heavy infestations of weevil are controlled with insecticides rather than by drainage, the depressing effects on yield of drainage and of root destruction by weevils would be avoided. While it remains to be proved, it would appear that under conditions of heavy infestations insecticidal control without drainage should materially increase yields. Should future work show that similar results may be regularly obtained, we may conclude that insecticidal control of the rice water weevil is more effective, is cheaper, produces higher yields, requires less water, and will materially lessen the mosquito populations of the rice area. 

Aldrin from Rice. An important off-take for aldrin is in the treatment of rice seed to protect the seedling against grape colaspis larvae and rice water weevils. The seed is usually sprayed with sufficient volume of an aldrin-hydrocarbon solution to give 2-4 oz. of aldrin per bushel of seed. The seed is either flown onto flooded fields or drilled into dry fields and then flooded. The planting rate, which determines the amount of aldrin applied per acre, will vary with the variety and local cultural practices. The fields are drained and reflooded a few times before harvest, the frequency depending upon the amount of rainfall and degree... 

CAS 1563-66-2. TM for a pesticide designed to combat com rootworm and rice water weevil. Approved by USDA. Also effective on alfalfa, sugarcane, rice, peanuts, and potatoes. 

The traditional insects from the CNI spectrum such as aphids, whiteflies, some thrips and beetles such as the rice water weevil from rice Lissoroptems oryzophilus) and the apple weevil Anthonomus pomorum) and micro-lepidopterans such as Phyllocnistis citrdla in citrus. 

In paddy rice, granular application of fipronil at 25-75 g ha provides control of virtually all major insect pests, including stem borers (Chilo spp., Tryporyza spp., Rupela spp., Ostrinia spp.), brown plant hopper (Nilapawata lugens), rice water weevil (Lissorhoptrus spp.), and thrips (Frankliniella spp., Stenchaetothrips spp., Thrips spp., etc.). 

Imidacloprid (1) provides additional control of Cokopteran spp. (e.g., rice water and tobacco weevil, Colorado potato beetle, rice leaf beetle, wrreworms, grubs and other soil beetles) and Dipterans spp. (e.g., fruit fly, beet fly, bean and onion fly) and of selected micro-lepidopteran species (e.g., citrus, apple and potato leaf miner), ants Hymenoptera spp.), termites Isoptera spp.), cockroaches, grasshoppers and crickets Orthoptera spp.) [53]. 

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