scholarly journals The dynamics of development of cotton bollworm (Helicoverpa armigera H?bner, 1805) and turnipmoth (Agrotis segetumSchif, 1775) (Lepidoptera; Noctuidae) in the sugar beet agrocenosis

Author(s):  
Gazı Galib Seliqe

There is comprehensive information about the dynamics of the development of cotton bollworm (Helicoverpa armigera) and turnip moth (Agrotis segetum) belonging to order Lepidoptera in the sugar beet agrocenosis. The seasonal and diurnal flying-dynamics of both species, harmful period of the caterpillars in the agrocenosis, and some biological characteristics have been investigated during the studies. Obtained results can have practical importance for the control of these pests.

2020 ◽  
Vol 113 (5) ◽  
pp. 2086-2095
Author(s):  
Bita Valizadeh ◽  
Samira Samarfard ◽  
Jalal Jalali Sendi ◽  
Thomas P Karbanowicz

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.


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