Bollworm, cotton

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. 

Different lines, each with Insect resistance, may possess different ratios of antibiotic compounds. Thus, It may be possible to Increase resistance by crossing lines where each contributes genes for biosynthesis of different antibiotic compounds. The tobacco budworm was selected for study In preference to the cotton bollworm because It Is easier to rear and use In the laboratory, Is more resistant to Insecticides In the field, and It Is approximately as susceptible to cotton constituents Incorporated In laboratory diets (14). This present study was carried out to Identify and analyze for cotton constituents that were toxic In laboratory feeding tests, and to determine whether there were positive correlations of their content In leaves and/or other tissue with field resistance. From this Information, the generation of lines with multiple factors for resistance could be Initiated. 

Cotton bollworm (Heliothis armigera) S (11Z)-hexadec-11-enal F (9Z)-hexadec-9-enal... 

Resistance to py rethroids can also be in part attributed to reduced penetration in insects. Ahmad et al. (2006) found that delayed cuticular penetration played an important role in deltamethrin resistance in Chinese and Parkinson strains of the cotton bollworm, Helicov-erpa armigera. The half-time for applied deltamethrin was 1 hr for the susceptible strain and 6 hr for both of the resistant strains. 

Genetically modified, insect resistant cotton expressing the Cry 1 Ac protein provides protection against several of the major insect pests in U.S. cotton the pink bollworm, cotton bollworm, and tobacco budworm. Given their strongly resembling appearance. 

While many chewing insects are controlled by 24,055, even here there are limitations. If the insect attacks by penetrating the surface and feeding inside, control is not obtained. Pests which feed inside the fruit, such as the cotton bollworm, the corn borer, and the plum curculio—all chewing insects—take such a small amount of the treated surface before eating their way into the interior of the fruit, that control is difficult with an antifeeding compound. 

Corylus americana. See Filbert Corylus avellana. See Filbert Cosmos, 81-82 Coloneaster. 82-83 Cotoneaster webworms, 82 Cotton bollworms, viral pathogens for,... 

Because pheromones are used by female insects to indicate their state of fertile readiness, pheromones have proven to be an effective weapon in controlling some crop-damaging insects. For example, when a specific mating pheromone is applied to crops, male cotton bollworms and female tobacco budworms compulsively mate with one another. Because of physical incompatibilities, their bodies become interlocked and both insects eventually die. Less drastic uses of pheromones to control crop damage involve baiting traps... 

Chemical communication is not confined to the insect world. Female dogs secrete the chemical p-hydroxybenzoate to attract males. Just like the ants and cotton bollworms, who are dependent on detecting chemicals for their actions, male dogs will attempt to mate with various objects to which p-hydroxybenzoate has been apphed. 

Many baculoviruses126 (i.e., insect viruses) are species-specific. They have been used for the successful control of the gypsy moth, velvet bean caterpillar (on 5.9 million ha of soybeans in Brazil), cotton bollworm, codling moth (on apples, pears, and walnuts), rhinoceros beetle, potato tuber moth, sawflies, and porina moth.127 The gypsy moth was introduced into the United States in Massachusetts from Europe in 1869. It defoliates many trees if there are no checks on its population. The war against it has often used diflubenzuron ( dimilin1 ) (11.20), which affects many nontarget species.128... 

The cotton bollworm, Helicoverpa armigera, in Australia is of great economic importance and is cross-resistant to parathion-methyl and profenofos, but not to chlorpyrifos. It has an acetylcholinesterase with low sensitivity to paraoxon-methyl and profenofos, but the sensitivity to chlorpyrifos is unaltered. As Table 9.3 shows, the enzyme of the resistant insects is a little less efficient by having a slightly higher Km. (Km is the substrate concentration at which an enzyme-catalyzed reaction proceeds at one-half its maximum velocity.) This indicates a somewhat less efficient enzyme, but the difference is so slight that it does not cause any reduced fitness for the insects. The amount of and activity of acetylcholinesterase are almost always much higher than strictly necessary. 

Certain limonoids also possess an antifeedant activity against insect pests such as fall armyworm, cotton bollworm and spruce budworm (29, 30). Limonoids do not directly kill the pests, but gradually lower their growth rates. 

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