scholarly journals Attraction of the cotton bollworm, Helicoverpa armigera(Huebner)(Lepidoptera: Noctuidae), to volatiles from wilted leaves of a non-host plant, Pterocarya stenoptera.

2002 ◽  
Vol 37 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Chun Xiao ◽  
Peter C. Gregg ◽  
Wenli Hu ◽  
Zhihua Yang ◽  
Zhongning Zhang
Keyword(s):  
Host Plant ◽  
Helicoverpa Armigera ◽  
Cotton Bollworm ◽  
Helicoverpa Armígera ◽  
Pterocarya Stenoptera ◽  
Lepidoptera Noctuidae

Broad-scale suppression of cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae), associated with Bt cotton crops in Northern New South Wales, Australia

2016 ◽  
Vol 107 (2) ◽  
pp. 188-199 ◽  
Author(s):  
G.H. Baker ◽  
C.R. Tann
Keyword(s):  
Host Plant ◽  
Helicoverpa Armigera ◽  
Cotton Bollworm ◽  
Bt Cotton ◽  
Cotton Production ◽  
Bt Toxin ◽  
Pheromone Trapping ◽  
Eastern Australia ◽  
Helicoverpa Armígera ◽  
Broad Scale

AbstractThe cotton bollworm, Helicoverpa armigera, is a major pest of many agricultural crops in several countries, including Australia. Transgenic cotton, expressing a single Bt toxin, was first used in the 1990s to control H. armigera and other lepidopteran pests. Landscape scale or greater pest suppression has been reported in some countries using this technology. However, a long-term, broad-scale pheromone trapping program for H. armigera in a mixed cropping region in eastern Australia caught more moths during the deployment of single Bt toxin cotton (Ingard®) (1996–2004) than in previous years. This response can be attributed, at least in part, to (1) a precautionary cap (30% of total cotton grown, by area) being applied to Ingard® to restrict the development of Bt resistance in the pest, and (2) during the Ingard® era, cotton production greatly increased (as did that of another host plant, sorghum) and H. armigera (in particular the 3rd and older generations) responded in concert with this increase in host plant availability. However, with the replacement of Ingard® with Bollgard II® cotton (containing two different Bt toxins) in 2005, and recovery of the cotton industry from prevailing drought, H. armigera failed to track increased host-plant supply and moth numbers decreased. Greater toxicity of the two gene product, introduction of no cap on Bt cotton proportion, and an increase in natural enemy abundance are suggested as the most likely mechanisms responsible for the suppression observed.

scholarly journals Developing an Ephestia kuehniella Hemocyte Cell Line to Assess the Bio-Insecticidal Potential of Microencapsulated Helicoverpa armigera Nucleopolyhedrovirus Against Cotton Bollworm (Lepidoptera: Noctuidae) Larva

2020 ◽  
Vol 113 (5) ◽  
pp. 2086-2095
Author(s):  
Bita Valizadeh ◽  
Samira Samarfard ◽  
Jalal Jalali Sendi ◽  
Thomas P Karbanowicz
Keyword(s):  
Cell Line ◽  
Helicoverpa Armigera ◽  
Ephestia Kuehniella ◽  
Cotton Bollworm ◽  
Population Doubling ◽  
Logarithmic Phase ◽  
Population Doubling Time ◽  
Cottonseed Kernel ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae

Abstract Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) (genus: Alphabaculovirus, incertae sedis: Baculoviridae) has been used to control Helicoverpa armigera (Hübner). A reproducible and susceptible cell line was prepared from the hemocytes of Ephestia kuehniella in Grace and Ex-Cell 420 media. The population doubling time of these cloned cell cultures during the logarithmic phase were about 2.3 and 3.7 d for Ex-Cell 420 and Grace’s media, respectively. When 60% confluence occurred, cells were infected by viral inoculums. All biochemical compounds were significantly changed relevant to cellular metabolism due to HearNPV infection. In order to improve its stability, two polymer formulations were used, i.e., formulation A (sodium alginate, gelatin, starch, and molasses) and formulation B (cottonseed kernel extract, Bran, glycerol, boric acid, egg white, and sugar). Formulant A provided high photostability by exhibiting 83.2 ± 3% efficacy and 88.66 ± 2.1% original activities remaining after 72 h UV exposure. Percentage original activity remaining of unformulated HearNPV and formulated mixture of B was 38.66 ± 2.6% and 9.33 ± 1.3%, respectively, after 72 h UV-irradiation. The virulence of the HearNPV proliferated from the Ex-Cell medium was similar to the virulence of wild-type HearNPV with LC50 of 7.7×105 OBs/ml. Formulant A, revealed only 20.0 ± 1% reduction in efficacy while the unformulated virus and formulant B faced a reduction of 90.0 ± 3% and 64.0 ± 2% after 72 h of UVA irradiation. Formulant A thus showed a high potential to protect HearNPVs microparticles against UV-inactivation suggesting a new platform for more efficient biological-management of cotton bollworm (specific name Helicoverpa armigera, genus: Helicoverpa, Lepidoptera: Noctuidae) in vivo.

Effects of egg load on the host-selection behaviour of Helicoverpa armigera (HÜbner) (Lepidoptera : Noctuidae)

1998 ◽  
Vol 46 (3) ◽  
pp. 291 ◽  
Author(s):  
Mustapha F. A. Jallow ◽  
Myron P. Zalucki
Keyword(s):  
Host Plant ◽  
Helicoverpa Armigera ◽  
Physiological State ◽  
Egg Load ◽  
Host Plant Selection ◽  
Plant Selection ◽  
Helicoverpa Armígera ◽  
Host Plant Specificity ◽  
Lepidoptera Noctuidae ◽  
Effect Of Age

We examined the effect of age-specific fecundity, mated status, and egg load on host-plant selection by Helicoverpa armigera under laboratory conditions. The physiological state of a female moth (number of mature eggs produced) greatly influences her host-plant specificity and propensity to oviposit (oviposition motivation). Female moths were less discriminating against cowpea (a low-ranked host) relative to maize (a high-ranked host) as egg load increased. Similarly, increased egg load led to a greater propensity to oviposit on both cowpea and maize. Distribution of oviposition with age of mated females peaked shortly after mating and declined steadily thereafter until death. Most mated females (88%) carried only a single spermat-ophore, a few females (12%) contained two. The significance of these findings in relation to host-plant selection by H. armigera, and its management, are discussed.

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