1887

n African Entomology - Interaction of spinosad and Bacillus thuringiensis on certain toxicological, biochemical and molecular aspects in the Egyptian cotton leaf worm, Spodoptera littoralis (Boisduval) (Lepidoptera : Noctuidae)

Volume 27 Number 2
  • ISSN : 1021-3589
USD

 

Abstract

The cotton leaf worm, Spodoptera littoralis, is one of the most injurious agricultural pests in Egypt. In the present study, the interaction between spinosad and Bacillus thuringiensis, using different pairings, in third and fifth instar larvae was determined. Activities of α- and β-non-specific esterases and acetylcholinesterase (AChE) were also determined. Additionally, AChE transcript abundance using the real-time polymerase chain reaction (PCR) was detected. The cumulative percentage mortality of S. littoralis, third and fifth instar larvae, to spinosad and B. thuringiensis were increased gradually by increasing the concentrations. Spinosad was more potent than B. thuringiensis. Sequential application of these bio-insecticides, on the LC25 level on third and fifth instar larvae, when spinosad was first applied, showed synergistic interaction and additive effect, respectively.On the other hand, when B. thuringiensis was first applied, using the same timing of application, additive interaction was observed for both third and fifth instars. Individual, simultaneous and sequential applications of these bio-insecticides induced variable changes in α- and β-esterases and AChE activities. Real-time PCR (qRT-PCR) revealed an increase in transcript abundance up to 2.0-fold in third instar larvae in case of sequential and simultaneous applications. Based on the results herein, integrated pest management programme using spinosad and B. thuringiensis can be successfully developed for the control of S. littoralis.

Loading full text...

Full text loading...

Loading

Article metrics loading...

/content/journal/10520/EJC-1878cd7492
2019-09-01
2019-10-14

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error