Weevils control

Such a practice is very favorable to the multiplication of rice field mosquitoes. It therefore becomes evident that if some method of weevil control other than drainage could be devised, it might be possible to control both insects with a single operation. 

These counts (32) clearly show that the treated plots contained far fewer larvae than either those drained for weevil control or the untreated and continuously flooded plots. The cost of the insecticidal treatment is believed to be less than half as much as draining, drying, and reflooding fields. Counts of mosquito larvae in all plots taken 4 days after the drained plots were reflooded showed less than 1% as many mosquitoes in the undrained plots as in those drained and reflooded. Less water was required for continuous flooding than for draining and reflooding. 

Dorough, H.W., Skrentny, R.F., and Pass. B.C. Residues in alfalfa and soils following treatment with technical chlordane and high purity chlordane (HCS 3260) for alfalfa weevil control, J. Agric. Food Chem., 20(l) 42-47, 1972. 

Uses. Insecticide for boll weevil control and termite control currently banned or severely restricted in many countries... 

Although pesticides continue to be the major approach to boll weevil control, problems related to their use have led to a search for alternative forms of pest control. These Include chemicals that modify behavior and/or development, biological agents, and genetic manipulation. 

Uses Insecticide acaricide EPA restricted-use pesticide esp. effective for boll weevil control Trade Name Synonyms Folidol M J[Bayer AG http //WWW. bayer-ag. de http //www.bayer.com]] ME 605-Spritzpulver t[Bayer CropScience AG http //WWW. bayercropscience. com]... 

While solid m.p. 95 -96 - C, soluble in organic solvents. An insecticide similar to chlordane. Used to control cotton boll weevil. 

Grandisol, with a four-membered ring, is another insect hormone, the male sex hormone of the boll weevil to be precise. It may also be useful as a highly specific pest control. How might it be made ... 

Monosodium methanearsonate (MSMA) [2163-80-6] CH AsONaOOH, disodium methanearsonate (DSMA) [144-21-8], CH2AsO(NaO)2, cacodyhc acid [75-60-5], (CH2)2AsOOH, and arsenic acid [7778-39-4], H AsO, are used ia agriculture appHcations (11,12). MSMA, DMSA, and cacodyUc acid are used as herbicides (qv) especially ia cotton (qv) fields for the control of Johnson and nutsedge grass and other weeds. Arsenic acid (13) and cacodyhc acid may be used as a desiccant for the defoHation of the cotton boU prior to harvesting. Calcium arsenate [7778-44-1], Ca2(As0 2> once an important chemical for the control of the boU weevil and cotton worm, has disappeared from appHcation and the use of lead arsenate [7784-40-9], Pb AsO, for fmit crops is currentiy restricted. 

Pests and Insecticides. The most destmctive pests of the cotton plant are the boU weevil and the boUworm/budworm complex. They are serious threats to the cotton industry in countries around the world. The boU weevil migrated from Mexico around 1892 and spread over the entire cotton belt within 30 years. The domestic cotton crop lost to the weevil is worth 200 million a year. In addition, about 75 million a year is spent for pesticides to control this destmctive pest (8). Unfortunately, some insecticides used to control the weevil kill many beneficial insects. Among the undesired casualties are insects that help to control the boUworm and the tobacco budworm, pests that cause another 200 million loss in cotton. 

In 1916, calcium arsenate [7778-44-1] dusted by airplane was used to control the boU weevil however, throughout many developments in effective insecticides, such as organophosphates, the boU weevils became resistant to poisons that were formerly effective (see Insectcontroltechnology). 

Although the boll weevil, a very serious cotton pest in the South, feeds voraciously on cotton squares and bolls in response to an at-tractant or attractants contained therein, these same cotton parts (49) contain also a boll weevil repellent that shows its effect once the at-tractant has volatilized completely. Department of Agriculture scientists are attempting to isolate and identify this repellent, which presumably could be applied to ward off weevil attack. Cotton seedlings painted with an aqueous emulsion of the material effectively repelled 100% of the weevils for 5 hours and only medium damage was evident after 12 hours, whereas control seedlings were completely destroyed after only 2 hours. 

DDT at 10 pounds per acre to control the bollworm, boll weevil, cotton fleahopper, tarnished plant bug, rapid plant bug, and some species of cutworms and thrips. (On cotton just up it was found that only 0.07 pound per acre of aldrin, applied as an emulsion, was necessary for the control of cutworms and thrips.) Significantly, no increase in aphid population was noted following the use of the aldrin-DDT mixture (4). 

Tests of dieldrin against cotton pests have not been as extensive, but the Mississippi 1950 Cotton Insect Control Recommendations state that it kills a larger proportion of immature weevils in squares than any other insecticide tested thus far and is considered very promising for cotton insect control (4). 

Stored grain losses caused by insects throughout the world total approximately 6,000,000 bushels a year. The development of new chemical methods for determining weevil infestation and the increased application of chemicals for the control of other pests are rapidly reducing these staggering losses. 

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. 

In an effort to develop some such control for weevils, a number of insecticides were tested to determine their effectiveness. In these tests aldrin, chlordan, dieldrin, and heptachlor at certain strengths each gave 90% or better control when applied to rice just previous to the first flooding. 

Previous work at this station had shown that when heavy weevil infestations were present, drainage properly timed to control weevils resulted in higher yields. Evidence has also been found that drainage in the absence of heavy infestations depresses yields. The yield data on the experimental plots showed that the undrained plots, both treated and untreated, yielded almost 5 bushels more per acre than the drained plots. The weevil infestation in the plots was very light in 1953, which probably accounts for the fact that yields were not increased by controlling weevils by the use of insecticides. 

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. 

Grain and foodstuffs are constantly attacked by weevils. Fumigation with carbon bisulfide, methyl bromide, and Chlorosol fumigant (a carbon tetrachloride-ethylene dibromide mixture) provides effective control where storage areas are built to handle these materials. Such storage equipment is limited, so there is need for an insecticide with low mammalian toxicity in order to achieve continuous protection by direct application. 

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