Biochemical characterization of spiromesifen and spirotetramat as lipid synthesis inhibitors on cotton leaf worm, Spodoptera littoralis

Ragaei M Abdel-Fatah,Samy M Mohamed,Atef A Aly,Al-Kazafy H Sabry

doi:10.1186/s42269-019-0107-9

Ragaei M Abdel-Fatah, Samy M Mohamed + Show 2 more

Open Access

https://doi.org/10.1186/s42269-019-0107-9

Copy DOI

Abstract

BackgroundTwo lipid synthesis inhibitors compounds (spiromesifen SPM and spirotetramat SPT) were used against the second instar larvae of cotton leaf worm, Spodoptera littoralis under laboratory condition. Toxicity of both compounds was tested. Effect of these insecticides on total lipid also was determined.ResultsThe obtained results showed that both compounds were moderately toxic against the second instar larvae of S. littoralis. The mortality percentages caused by the field rate of spiromesifen and spirotetramat were 51.7 and 60.0%, respectively. The lethal concentrations for 50% of tested insect population (LC50) were 170.1 and 42.2 ppm, respectively. The total lipid content was determined in treated larvae and compared with the untreated. The percentage of total lipid in spiromesifen- and spirotetramat-treated larvae was 2.17 and 2.21%, respectively, compared with 2.42% in untreated larvae. GC/MS also was used in identification of fatty acids composition of S. littoralis larvae.ConclusionThe results cleared that 13 fatty acids were identified in S. littoralis larvae. The obtained results showed significant difference in percentages of fatty acids with both treated and untreated larvae and also, between tested compounds. Some fatty acids were existed in untreated larvae but not existed in treated larvae.

Highlights

The Egyptian cotton plays an important role in Egyptian society by providing job opportunities and tradable goods to support the economy (Baffes 2005)
Toxicity of spiromesifen and spirotetramat to the second instar larvae of S. littoralis Recommended concentrations and two subrecommended concentrations of both tested insecticides are used against the second instar larvae of S. littoralis (Table 1)
Spiromesifen and spirotetramat were moderately toxic against the second instar larvae of S. littoralis

Summary

Introduction

The Egyptian cotton plays an important role in Egyptian society by providing job opportunities and tradable goods to support the economy (Baffes 2005). The cotton leaf worm is considered one of the most destructive pest that attacks the cotton crop (Horowitz et al 1995). The mode of action of this class is specific against the immature stages (Nauen et al 2008). These insecticides reduce the fecundity and fertility of treated insects which lead to reduce the insect populations. Two lipid synthesis inhibitors compounds (spiromesifen SPM and spirotetramat SPT) were used against the second instar larvae of cotton leaf worm, Spodoptera littoralis under laboratory condition. Effect of these insecticides on total lipid was determined

Objectives

Methods

Results

Discussion

Conclusion