scholarly journals Hormonal Effect on Cultivated Insect Tissues : III. Effects of α- and β-Ecdysone or Prothoracic Glands on Spermiogenesis in Two Noctuid Insects in vitro Lepidoptera : Noctuidae)

1975 ◽  
Vol 10 (3) ◽  
pp. 220-225 ◽  
Author(s):  
Tokunin FUKUSHIMA ◽  
Shigemi YAGI
2017 ◽  
Vol 17 (2) ◽  
Author(s):  
I Made Indra Agastya ◽  
Aminudin Afandhi ◽  
Luqman Qurata Aini

This research was conducted in vitro in the laboratory. Studies conducted in the Laboratory of Bacteriology Department of Plant Pests and Diseases of the Faculty of Agriculture, University of Brawijaya, on the effectiveness of the bacteria Bacillus cereus and Bacillus megaterium as biological pesticides controlling Spodoptera litura. The objective of this study was to determine the effectiveness of the bacteria Bacillus sp as biological control. Effectiveness pesticide was measured by testing the incubation period and mortality in larvae of S. litura instar 3. This study used a completely randomized design (CRD), conducted observations every 6 hours until the larvae dead. The results showed that the percentage of mortality of S. litura reached 94.66% compared to the control, while the incubation time of the bacteria B. cereus cause disease until 29.84 hours. B. cereus and B. megaterium have the ability to incubate third instar larvae of S. litura up to 29.84 hours and caused the death of larvae up to 94.66%. Keywords: Biological pesticides, Bacillus cereus, Bacillus megaterium, entomopatogen, Spodoptera litura


2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Marisa Nardiello ◽  
Rosanna Salvia ◽  
Andrea Scala ◽  
Carmen Scieuzo ◽  
Sabino Aurelio Bufo ◽  
...  

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.


1991 ◽  
Vol 21 (1) ◽  
pp. 41-51 ◽  
Author(s):  
M.L. Grieneisen ◽  
J.T. Warren ◽  
S. Sakurai ◽  
L.I. Gilbert

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