Mode of Action of Bacillus Thuringiensis and Nuclear Polyhedrosis Virus in the Larvae of Spodoptera Littoralis (Boisd.)

  • H. S. Salama
  • A. Sharaby
  • M. Magd El-Din


An additive effect was obtained after treatment of Spodoptera littoralis (Boisd.) larvae with a combination of Bacillus thuringiensis and nuclear poly hedrosis virus (NPVs). The NPVs was the more pathogenic followed by B. t., cytopathologically. Simultaneous application of B. t. and NPVs affected the midgut cells by causing a very specific appearance of cell hypertrophy with some deposits of B. t. crystals on the fourth day of infection as shown by scanning electron microscopy. Transmission electron microscopy showed that the vegetative cells and spores of B. t. entered the midgut epithelial cells followed by the virus. It is possible that the initial destruction caused by the B. t. toxin facilitated penetration and entry of the virus.

Key Words

Additive effect nuclear polyhedrosis virus Bacillus thuringiensis Spodoptera littoralis 


L’effet additionnel etait obtenue apres un traitement combine du Bacillus thuringiensis et le virus nuclear polyhedrosis (NPVs) contre la larve Spodoptera littoralis. Le viruse NPVs était le plus pathogenique puis etait B. t. Les effets cytopathologiques du traitement combine du B. t. et NPVs sur les cellules du midgutte (midgut) hypertrophie nombre de cristals de B. t. ont ete observees par le microscope (scanning electron microscopy). La transmission microscopicale electronique a montre que les cellules vegetatives et les spores du B. t. ont entre les cellules epitheliales du midgutte, ensuite le virus est rentre. Il est possible que les premieres destructions qui sont causes par le toxin de B. t. facilitent la penetration et l’entree de virus.


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Copyright information

© ICIPE 1993

Authors and Affiliations

  • H. S. Salama
    • 1
  • A. Sharaby
    • 2
  • M. Magd El-Din
    • 2
  1. 1.Department of Biology, Faculty of MedicineKing Abdul-Aziz UniversityJeddahUSA
  2. 2.Department of Pests and Plant ProtectionNational Research CentreDokki, CairoEgypt

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