The Monitoring and Molecular Identification of the Mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) on Okra Plants at Sharkia Governorate

Nabil, A,I Ismail,M Elashtokhy,M Hegab

doi:10.21608/eajbsc.2020.163663

Abstract

Mealybugs (Hemiptera: Pseudococcidae) are small piercing–sucking insects that infesting a wide range of crops and vegetables and their species are similar, which makes it difficult for non-specialists to distinguish between them. Samples were collected of infested okra plants from five districts at Sharkia Governorate, Egypt. This study aimed to study the distribution of the cotton mealybug, Phenacoccus solenopsis Tinsley and its associated parasitoid as well as the identification of this species by molecular characterization due to the high degree of morphological similarity between different closely related species of mealybugs. It was found that the Parasitism has a big influence on the occurrence of this insect infestation and this species of mealybug was confirmed by amplified and sequenced DNA loci known to be informative for species identification by provides information of 28S ribosomal RNA gene sequence. Consequently, the success of IPM programs against mealybugs depends on the correct definition of this pest through genetic characterization to choose the best control strategies. On the other hand, the difficulty of correctly identifying these species leads to its difficulty in choosing appropriate methods of control, especially biological control where each pest has a specific species of its natural enemy, which controls it biologically.

Highlights

Okra (Abelmoschus esculentus L.) is one of the major popular vegetables in Egypt.Incidence of mealybug pest, Phenacoccus solenopsis Tinsley on okra has been reported by many authors from different parts of the country while being responsible for considerable yield loss (Abd-Rabou et al, 2010; Ibrahim et al, 2015; Nabil et al, 2015 and Rezk et al., 2019)
This study aimed to study the distribution of the cotton mealybug, Phenacoccus solenopsis Tinsley and its associated parasitoid as well as the identification of this species by molecular characterization due to the high degree of morphological similarity between different closely related species of mealybugs
Phenacoccus solenopsis Tinsley on okra has been reported by many authors from different parts of the country while being responsible for considerable yield loss (Abd-Rabou et al, 2010; Ibrahim et al, 2015; Nabil et al, 2015 and Rezk et al, 2019)

Summary

Introduction

Okra (Abelmoschus esculentus L.) is one of the major popular vegetables in Egypt.Incidence of mealybug pest, Phenacoccus solenopsis Tinsley on okra has been reported by many authors from different parts of the country while being responsible for considerable yield loss (Abd-Rabou et al, 2010; Ibrahim et al, 2015; Nabil et al, 2015 and Rezk et al., 2019). The difficulty of correctly identifying these species affected selecting the suitable control strategies, biocontrol. This problem has led to the development of molecular tools used to obtain accurate identification of species of Pseudococcidae using DNA barcoding (Park et al, 2011; Abd-Rabou et al, 2012; Correa et al, 2012 and Pacheco Da Silva et al, 2014). This study helps us to further track the spread of this species in the region and provides 28s ribosomal RNA gene sequence of its This investigation has contributed to the development of new tools for mealybug characterization, but it remains difficult to evaluate the efficacy of different markers for distinguishing between closely related species of Pseudococcidae

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