Case study 5:Helicoverpa armigera — field management and history of invasion in Brazil

2016 ◽  
Author(s):  
Paulo E. Degrande
2005 ◽  
Vol 71 (5) ◽  
pp. 2558-2563 ◽  
Author(s):  
Robin V. Gunning ◽  
Ho T. Dang ◽  
Fred C. Kemp ◽  
Ian C. Nicholson ◽  
Graham D. Moores

ABSTRACT In Australia, the cotton bollworm, Helicoverpa armigera, has a long history of resistance to conventional insecticides. Transgenic cotton (expressing the Bacillus thuringiensis toxin Cry1Ac) has been grown for H. armigera control since 1996. It is demonstrated here that a population of Australian H. armigera has developed resistance to Cry1Ac toxin (275-fold). Some 70% of resistant H. armigera larvae were able to survive on Cry1Ac transgenic cotton (Ingard) The resistance phenotype is inherited as an autosomal semidominant trait. Resistance was associated with elevated esterase levels, which cosegregated with resistance. In vitro studies employing surface plasmon resonance technology and other biochemical techniques demonstrated that resistant strain esterase could bind to Cry1Ac protoxin and activated toxin. In vivo studies showed that Cry1Ac-resistant larvae fed Cy1Ac transgenic cotton or Cry1Ac-treated artificial diet had lower esterase activity than non-Cry1Ac-fed larvae. A resistance mechanism in which esterase sequesters Cry1Ac is proposed.


Author(s):  
Odile Moreau

This chapter explores movement and circulation across the Mediterranean and seeks to contribute to a history of proto-nationalism in the Maghrib and the Middle East at a particular moment prior to World War I. The discussion is particularly concerned with the interface of two Mediterranean spaces: the Middle East (Egypt, Ottoman Empire) and North Africa (Morocco), where the latter is viewed as a case study where resistance movements sought external allies as a way of compensating for their internal weakness. Applying methods developed by Subaltern Studies, and linking macro-historical approaches, namely of a translocal movement in the Muslim Mediterranean, it explores how the Egypt-based society, al-Ittihad al-Maghribi, through its agent, Aref Taher, used the press as an instrument for political propaganda, promoting its Pan-Islamic programme and its goal of uniting North Africa.


2010 ◽  
Vol 1 (1) ◽  
pp. 75-93
Author(s):  
Jessica Moberg

Immediately after the Second World War Sweden was struck by a wave of sightings of strange flying objects. In some cases these mass sightings resulted in panic, particularly after authorities failed to identify them. Decades later, these phenomena were interpreted by two members of the Swedish UFO movement, Erland Sandqvist and Gösta Rehn, as alien spaceships, or UFOs. Rehn argued that ‘[t]here is nothing so dramatic in the Swedish history of UFOs as this invasion of alien fly-things’ (Rehn 1969: 50). In this article the interpretation of such sightings proposed by these authors, namely that we are visited by extraterrestrials from outer space, is approached from the perspective of myth theory. According to this mythical theme, not only are we are not alone in the universe, but also the history of humankind has been shaped by encounters with more highly-evolved alien beings. In their modern day form, these kinds of ideas about aliens and UFOs originated in the United States. The reasoning of Sandqvist and Rehn exemplifies the localization process that took place as members of the Swedish UFO movement began to produce their own narratives about aliens and UFOs. The question I will address is: in what ways do these stories change in new contexts? Texts produced by the Swedish UFO movement are analyzed as a case study of this process.


Author(s):  
Nihad H. Mutlag ◽  
Ameer S. A. Al-Haddad

A field study was conducted to evaluate the efficiency of four microbial insecticides viz. Beauveria bassiana; HaNPV (Helicoverpa armigera Nuclear Polyhedrosis virus); (Bacillus thuringiensisvar.kurstaki 2 gm/L); HaNPV+Bt; neem oil; neem cake and D.D.V.P EC 76% @0.05% at Research Farm SHIATS,Allahabad during rabi season of 2011-2012. The experiment was laid out in randomized block design with seven treatment and replicated thrice. The observation larval populations of H. armigera were recorded one day before treatment was recorded at 3,7, and 10 days after treatments. The larva population of H. armigera appeared in the third week of February (8 the Standard week) and reached its peak of 14.65 larvae in first week of April and decline rapidly with maturation of crop. There was only one peak in the larval population observation in the 1st week. Bacillus thuringiensis was the most effective chemical by D.D.V.P.76%@0.05% . Among the microbial insecticides. HaNPV ,was the most effective followed by HaNPV+Bt and neem cake . The combination treatments were less effective than the individual treatment neem oil and B. bassiana were the least effective treatment in reducing the larval population of Heliverpa armigera.


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