Pathogenicity of three entomopathogenic fungi, to the aphid species, Metopolophium dirhodum (Walker) (Hemiptera: Aphididae), and their Alkaline protease activities

Ouidad Abdelaziz,Amar Oufroukh,Fayza Kouadri,Mohamed Mourad Senoussi,Ali Kemal Birgücü,Abderrahmane Bensegueni,Benkenana Naima,İsmail Karaca

doi:10.1186/s41938-018-0030-7

Abstract

The aim of the present study is to investigate the effect of three entomopathogenic fungi (EPF) (Beauveria bassiana, Cladosporium cladosporioides, and Verticillium alfalfae) on the aphid species, Metopolophium dirhodum (Walker) (Hemiptera: Aphididae). The selected EPF were isolated from the agricultural soil of the National Institute of Plant Protection (INPV) in Constantine, Algeria, and were tested against the aphid insects that were collected from the same area. The aphid species M. dirhodum were exposed to each fungal spore suspensions 107 conidia/ml for 10 s. Percent mortality was recorded at 1, 3, 5, and 7 days post treatment. Percentage mortalities, 7 days post treatment, were 95.83, 63.98, and 51.83% by B. bassiana, C. cladosporioides, and V. alfalfae, respectively. The higher protease activities were observed for isolate V. alfalfae with 95 U/ml, followed by B. bassiana with 38.26 U/ml, and finally C. cladosporioides with 35, 65 U/ml. The results presented in this study revealed that there was no relation between high alkaline protease activities and high virulence isolates.

Highlights

IntroductionM. dirhodum is the most important species that could destroy grains all over the world (Dixon 1987)
The aphids are the most harmful insects that affect wheat plants
Fungal isolates The virulence of three fungal isolates (Beauveria bassiana, Cladosporium cladosporioides, and Verticillium alfalfae) was tested

Summary

Introduction

M. dirhodum is the most important species that could destroy grains all over the world (Dixon 1987). It chooses its host during the cold season and emigrates toward drought cereals in summer and is able to transmit a Luteovirus and provides a wide resistance against exterminators (Carter et al 1980). The biocontrol methods, using entomopathoganic fungi (EPF), are among the most effective ones (Wells et al 2000). The efficiency of these fungi lies in the fact that they can fight against exterminators by invading insect crusts. They usually infect insects by active penetration through the cuticle and are able to control insects regarding their feeding environment

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Conclusion