Insecticidal and inhibitory effects of Meliaceae and Asteraceae extracts to silverleaf whitefly

Edson Luiz Lopes Baldin,João Luis Callegari Lopes,Eunice Cláudia Schlick-Souza,Paulo César Bogorni,Norberto Peporine Lopes,Muriel Cicatti Emanoeli Soares,José Djair Vendramim

doi:10.1590/s0102-053620200307

Abstract

ABSTRACT Bemisia tabaci (Hemiptera: Aleyrodidae) is a polyphagous insect that causes direct and indirect damage on tomato. Spraying with synthetic insecticides is one of the main control tools for the whitefly; however, the abusive use of this tool can impact the environment and human beings. In this study we evaluated the bioactivity of extracts from plant species from Asteraceae and Meliaceae families on B. tabaci biotype B in tomato. A preliminary bioassay evaluated the effects of the extracts at 2% (w/v) on infestation and oviposition of this whitefly. Then, the nymphicidal and ovicidal effects of the chloroformic extract of Trichilia pallida - TP-Cl at six concentrations were performed. Finally, the TP-Cl LC50 was estimated. All extracts were repellent to the whitefly, except that ones from T. pallida (ethanolic) and Melia azedarach (hexanic), considered neutral at 24 h. All the extracts caused deterrence of oviposition. All concentrations of TP-Cl revealed nymphicidal activity and the highest ones provided the lowest egg viability averages. The estimated LC50 was 0.0955%. These results provide evidence for the potential of the extracts to be used as alternative control agents of B. tabaci biotype B in tomatoes.

Highlights

Bemisia tabaci (Hemiptera: Aleyrodidae) é um inseto polífago que causa danos diretos e indiretos na cultura do tomateiro
Due to the high damage potential of this pest on tomato and the lack of control by less aggressive control methods in relation to the use of synthetic insecticides, this study evaluated the bioactivity of organic extracts of Meliaceae and Asteraceae species on B. tabaci biotype B
A significant reduction in the number of B. tabaci adults was observed when tomato leaflets were sprayed with aqueous extracts (2% w/v) from seeds of A. indica and leaves and branches of T. pallida compared to the control (Baldin et al, 2007b)

Summary

Introduction

Bemisia tabaci (Hemiptera: Aleyrodidae) é um inseto polífago que causa danos diretos e indiretos na cultura do tomateiro. A significant reduction in the number of B. tabaci adults was observed when tomato leaflets were sprayed with aqueous extracts (2% w/v) from seeds of A. indica and leaves and branches of T. pallida compared to the control (Baldin et al, 2007b).

Results

Conclusion