Tobacco budworm growth

Relative Effects of Cotton Flower Petal Constituents on Tobacco Budworm Growth and Survival /... 

Table III. Tobacco Budworm Growth Inhibition by Compounds Isolated ...

Inhibition of Tobacco Budworm Larval Growth by Cotton Constituents BD5Q as Percent of Diet ... 

Nagilactones from Podocarpus nagi and their effects on the feeding and growth of tobacco budworm. Zhang, M. Ying, B. P. Kubo, I. J. Nat. Prod. 1992, 55, 1057-1062. 

The effect of these resistances has been to drive chemical control from one insecticide to the next. In most parts of the Nile delta the cotton leafworms can still be controlled by some OP compound, such as chlorpyrifos, supplemented where necessary with the insect growth regulator Dimilin. But in southern Texas, Mexico, Nicaragua and Peru the multiple resistances of the tobacco budworm, and to a less extreme degree of H. zea and Spodoptera sunia, have made even 20 insecticide applications a season quite worthless, and indeed there is less damage to the cotton if no chemicals are applied at all. The only materials that can be relied upon to kill these multiresistant H. viresoens are the dichlorovinyl pyrethroid NRDC-143 and the Heliothis nuclear polyhedrosis virus. 

The multiresistant strains now extant also show a certain cross-tolerance, but not resistance, to the third-generation insecticides such as the juvenile-hormone mimics and other so-called insect growth regulators, as was found in strains of the housefly, flour beetle and tobacco budworm. Resistance to the JH mimic methoprene and Monsanto-585 has been induced by laboratory selection of Culex taxsalis (28) and Culex pipiens (29), and to Monsanto-585 in Culex quinquefasstatus (30). Whatever insect or IGR is chosen, the result of exposure to selective doses in successive generations is usually the development of resistance, repeating our previous experience with chemosterilants, and the... 

The boll weevil antifeedants, anthranilic acid, gentisic acid, senecioic acid, trans-cinnamic acid, trans-cinnamaldehyde and camphor have been Isolated from the Peruvian plant Alchornea triplinervia (Euphorbiaceae). Anthranilic acid and camphor also showed significant Inhibition of growth of the tobacco budworm. 

Recent studies have confirmed that the phytoalexin isolated from species of cotton (Go55ypmw) infected with the fungus Verticillium dahliae is hemigossypol (161) (cf. Vol. 6, p. 66) and not, as previously reported,isohemigossypol (162). A related compound, p-hemigossypolone (163) has been identified as one of the compounds which inhibits the growth of tobacco budworm (Heliothis virescens)in cotton buds. ... 

Homeosoma electellum) contain high concentrations of tra-chyloban-19-oic acid (70) and ( —)-16-kauren-19-oic acid (71) in their florets. As sunflower florets that contain only small amounts of these compounds are a major portion of the diet of first instar larvae of this insect, it is likely that these acids serve as feeding inhibitors. At the 1% level, both kaurenoic and trachylobanoic acids decreased the growth of sunflower moth larvae and tobacco budworm (Heliothis virescens) by about 50%. At the 0.5% level, both reduced larval growth of the cotton bollworm and the pink bollworm to less than 5% (Fig. 22.23) (Mabry and Gill, 1979). The Z-and -isomers of (- )-ozic acid (72) have been isolated from Helianthus occidentalis and may be associated with resistance to insect attack (Stipanovic et al., 1979). 

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