Bollgard Cotton and Resistance of Tobacco Budworm (Lepidoptera: Noctuidae) to Conventional Insecticides in Southern Tamaulipas, Mexico

2005 ◽  
Vol 98 (6) ◽  
pp. 2203-2209 ◽  
Author(s):  
A. P. Terán-vargas ◽  
J. C. Rodríguez ◽  
C. A. Blanco ◽  
J. L. Martínez-carrillo ◽  
J. Cibrián-tovar ◽  
...  
Keyword(s):  
Tobacco Budworm ◽  
Lepidoptera Noctuidae

scholarly journals Attraction of Tobacco Budworm Moths (Lepidoptera: Noctuidae) to Jaggery, a Palm Sugar Extract

1997 ◽  
Vol 80 (3) ◽  
pp. 402 ◽  
Author(s):  
P. J. Landolt ◽  
E. R. Mitchell
Keyword(s):  
Tobacco Budworm ◽  
Palm Sugar ◽  
Lepidoptera Noctuidae

Effects of the sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta (Lepidoptera, Noctuidae)

2001 ◽  
Vol 204 (22) ◽  
pp. 3935-3942 ◽  
Author(s):  
Seong Eun Jeong ◽  
Yun Lee ◽  
Jeong Hee Hwang ◽  
Douglas C. Knipple
Keyword(s):  
Male Fertility ◽  
Chemical Constituents ◽  
Direct Injection ◽  
Arginine Decarboxylase ◽  
Tobacco Budworm ◽  
Polyamine Metabolism ◽  
Helicoverpa Assulta ◽  
Continuous Feeding ◽  
The Common ◽  
Lepidoptera Noctuidae

SUMMARY We investigated the effects of sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta. We found that continuous feeding of oleander sap during the larval period significantly affects fertility in males but not in females. This effect was also induced by direct injection of oleander sap into the hemocoel of 2-day-old pupae. Histological analyses of developing testes following oleander injection revealed a developmental delay and progressively more severe morphological abnormalities in the later stages of development. The effects of oleander sap on spermatogenesis in H. assulta were associated with greatly reduced levels of the two major polyamines, spermidine and spermine, in testis compared with saline-injected controls. In contrast, levels of putrescine, which is a precursor of both spermidine and spermine, and the activities of the enzymes ornithine decarboxylase and arginine decarboxylase, which are involved in the biosynthesis of putrescine, were initially elevated following oleander injection, but subsequently failed to undergo the induction that normally occurs during late pupal development. The effects of oleander sap on spermidine and spermine levels could be the result of direct inhibition by chemical constituents of the oleander sap of one of the enzymes used in common in the conversions of putrescine to spermidine and spermidine to spermine; alternatively, these effects on polyamine metabolism could be secondary to the disruption of a more fundamental process in the developmental program guiding spermatogenesis in H. assulta.

Inheritance, Stability, and Reversion of Insecticide Resistance in Tobacco Budworm (Lepidoptera: Noctuidae) Field Populations

1994 ◽  
Vol 87 (3) ◽  
pp. 551-558 ◽  
Author(s):  
G. W. Elzen ◽  
S. H. Martin ◽  
B. R. Leonard ◽  
J. B. Graves
Keyword(s):  
Insecticide Resistance ◽  
Tobacco Budworm ◽  
Lepidoptera Noctuidae

scholarly journals Ecdysteroidogenesis in Heliothis virescens (Lepidoptera: Noctuidae): Recombinant Prothoracicotropic Hormone and Brain Extract Show Comparable Effects

2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Marisa Nardiello ◽  
Rosanna Salvia ◽  
Andrea Scala ◽  
Carmen Scieuzo ◽  
Sabino Aurelio Bufo ◽  
...  
Keyword(s):  
Heliothis Virescens ◽  
Complex Mixture ◽  
Prothoracic Gland ◽  
Tobacco Budworm ◽  
Brain Extract ◽  
In Vitro Tests ◽  
Prothoracicotropic Hormone ◽  
Lepidoptera Noctuidae

Abstract Prothoracicotropic hormone (PTTH) is a neuropeptide that triggers a cascade of events within the prothoracic gland (PG) cells, leading to the activation of all the crucial enzymes involved in ecdysone biosynthesis, the main insect steroid hormone. Studies concerning ecdysteroidogenesis predicted PTTH action using brain extract (BE), consisting in a complex mixture in which some components positively or negatively interfere with PTTH-stimulated ecdysteroidogenesis. Consequently, the integration of these opposing factors in steroidogenic tissues leads to a complex secretory pattern. A recombinant form of prothoracicotropic hormone (rPTTH) from the tobacco budworm Heliothis virescens (F.) (Lepidoptera: Noctuidae) was expressed and purified to perform in vitro tests in a standard and repeatable manner. A characterization of rPTTH primary and secondary structures was performed. The ability of rPTTH and H. virescens BE to stimulate ecdysteroidogenesis was investigated on the third day of fifth larval stage. rPTTH activity was compared with the BE mixture by enzyme immunoassay and western blot, revealing that they equally stimulate the production of significant amount of ecdysone, through a transduction cascade that includes the TOR pathway, by the phosphorylation of 4E binding protein (4E-BP) and S6 kinase (S6K), the main targets of TOR protein. The results of these experiments suggest the importance of obtaining a functional pure hormone to perform further studies, not depending on the crude brain extract, composed by different elements and susceptible to different uncontrollable variables.

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