Bollworm

Boiler yater treatment Boiling point elevation Bois de Rose oil Bois de rose oil Boll weevil Bollworm Bologna Bolometer Bolometers... 

The preparation of the sex pheromone of the bollworm moth, ( )-9,ll-dodecadien-l-yl acetate, from compound A has been described. Suggest suitable reagents for each step in this sequence. 

In addition to the synthetic applications related to the stereoselective or stereospecific syntheses of various systems, especially natural products, described in the previous subsection, a number of general synthetic uses of the reversible [2,3]-sigmatropic rearrangement of allylic sulfoxides are presented below. Several investigators110-113 have employed the allylic sulfenate-to-sulfoxide equilibrium in combination with the syn elimination of the latter as a method for the synthesis of conjugated dienes. For example, Reich and coworkers110,111 have reported a detailed study on the conversion of allylic alcohols to 1,3-dienes by sequential sulfenate sulfoxide rearrangement and syn elimination of the sulfoxide. This method of mild and efficient 1,4-dehydration of allylic alcohols has also been shown to proceed with overall cis stereochemistry in cyclic systems, as illustrated by equation 25. The reaction of trans-46 proceeds almost instantaneously at room temperature, while that of the cis-alcohol is much slower. This method has been subsequently applied for the synthesis of several natural products, such as the stereoselective transformation of the allylic alcohol 48 into the sex pheromone of the Red Bollworm Moth (49)112 and the conversion of isocodeine (50) into 6-demethoxythebaine (51)113. 

Pi oblem The pheromone gossyplure (21) of the pink bollworm moth is a mixture of double bond isomers at bond (a). The c-is double bond (b) can be made from an acetylene so disconnection (24c) is suggested, Hou would you make both cis and trans (23) ... 

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). 

A SN reaction-based domino route to clerodane diterpenoid tanabalin (2-488) [258] has been described by Watanabe s group (Scheme 2.111) [259]. This natural product is interesting as it exhibits potent insect antifeedant activity against the pink bollworm, Pectinophora gossypiella, a severe pest of the cotton plant The domino sequence towards the substituted trans-decalin 2-487 as the key scaffold is induced by an intermolecular alkylation of the (5-ke toes ter 2-484 with the iodoalkane 2-483 followed by an intramolecular Michael addition/aldol condensation (Robin-... 

Bollworm/budworm complex, 5 9 Bolometers, 19 143-144 Bolton-Hunter reagent, 21 274 Boltzmann distribution, 14 657 26 1035 Boltzmann s constant, 26 1035 numerical value of, 24 434 Boltzmann s law, 14 662 Bolzano magnesium manufacturing process, 15 342... 

Endrin was introduced in the United States in 1951 as an avicide, rodenticide and insecticide. Its principal use to control the cotton bollworm and tobacco budworm peaked in the early 1970s. In 1979, the EPA canceled some uses of endrin and indicated its intent to cancel all uses of endrin (EPA 1979f USDA 1995). By 1986, all uses were voluntarily canceled (Bishop 1984, 1985, 1986 EPA 1993e USDA 1995), except for its use as a toxicant on bird perches, which was canceled in 1991 (USDA 1995). Endrin also was a contaminant in dieldrin (Verschueren 1983) however, all uses of this pesticide have been canceled since the mid-1980s (EPA 1992b). Consequently, there are no longer any significant releases of endrin to the environment in the United States. 

The pink bollworm (Pectinophora gossypiella Saund.), considered to be potentially the worst pest of cotton in the United States, occurs throughout the major cotton-producing areas in Mexico, Venezuela, Colombia, Brazil, and Argentina. It probably causes more damage to cotton in the tropical Americas than any other insect. 

Several species of lepidopterous larvae cause bollworm-type injury to bolls and squares throughout the tropics. They include the bollworm [Heliothis armigera (Hbn.)], the tobacco budworm [Heliothis virescens (F.)], the black bollworm (Pro-denia latisfascia Wlk.), and in Peru Mescinia peruella Schaus. 

Uses Nonsystemic insecticide and acaricide used to control bollworms, Alabama argillacea in cotton, and Chilo spp. in rice and other leaf-eating larvae in vegetables and fruits (Worthing and Hance, 1991). 

Cuts from the silica gel column were incorporated into artificial diets optimized for several economically-important agricultural pest insects, the pink bollworm Pectinophora gossypiella> the tobacco budworm Heliothis virescens> the corn earworm H. zea and the fall armyworm Spodoptera frugiperda. > Monitoring with this artificial diet bioassay, further column chromatography and preparative TLC on silica gel in diethylether-petrol yielded five... 

Insects may emit as little as 10 g of pheromone and a female insect contains typically only 50 mg of the material. The structure is sometimes exacting, as in the case of the pink bollworm, where the ratio of cis and trans double bonds is species specific to avoid hybridization of insects. 

While the above observation is interesting and could possibly have some implications for the control of the pink bollworm, the complexity of the steroid nucleus of ponasterone A and other molting hormone analogs and their weak insecticidal effect when applied topically or administered orally to most species of economically important insects may preclude their commercialization. The only commercial use of the molting hormone analogs thus far has been in the sericultural industry for the synchronization of cocoon spinning of silkworm colonies (17). 

Figure 7. Electron Micrograph Illustrating Ecdysls Inhibition of a Larva of the Pink Bollworm, Pectlnophora gossyplella after Ingestion of 2 ppm Ponasterone A In an Artificial Diet (Magnification x 100)...

The growth-inhibitory activity of azadirachtin fed in artificial diet to three species of agricultural pests, gossypiella, H. zea, and frugiperda, was compared to the activity of a number of limonoids isolated from plants in the Meliaceae and the Rutaceae (Table VI). After azadirachtin, the most active limonoid was cedrelone (Figure 13). Cedrelone was unique among the compounds tested in Table VI since it was the only limonoid, besides azadirachtin, to cause an inhibition in ecdysis (LC50 = 150 ppm) when fed to pink bollworm larvae (54). 

Insecticidal control of the pink bollworm is yet another management practice used by growers in Arizona pink bollworm exit holes in cotton bolls might provide portals of entry for A. flavus (55). Unfortunately, it is not economically feasible to achieve 100% control of the pink bollworm in cotton through the hi -ftequency use of insecticides, and even relatively low levels of infestation by this insect pest is well correlated to high levels of A. flavus infection and subsequent aflatoxin contamination. 

Immature bolls were inoculated via simulated pink bollworm exit holes in the greenhouse. Equal quantities of spores of each strain were used. Seed were harvested and analyzed... 

Cook was among the first to propose that the pigment glands of cotton might act as a repellant to the bollworm (266). 

Cotton 2,4-D (Amine) Pink Bollworm Defoli ation (33,34)... 

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