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Entomopathogenic fungi (EPF) represent the future of pest control, as they have the capacity to induce serious infections in insects, trigger epizootics, and effectively manage insect populations. The study aimed to identify and test indigenous EPF isolates against Tribolium confusum using soil samples from Northwestern and central Saudi Arabia. Galleria mellonella larvae were used as insect bait to collect EPF from soil samples from date palm groves, fruit groves, and maise fields. Only 27.3% of soil samples tested positive for palm grove-originating EPFs. Polymerase chain reaction (PCR) identified the cultured fungi as Metarhizium anisopliae and Beauveria bassiana. Tribolium confusum pathogenicity was assessed using nine local fungal isolates. Different fungus isolates were tested for their pathogenicity on larval and adult T. confusum. The results showed that M. anisopliae MaSA-2, MaSA-3, and MaSA-4 had infection rates of 85%, 85%, and 75%, respectively, in last-instar T. confusum larvae and 5%, 10%, and 20% in adults within seven days. On the other hand, B. bassiana BbSA-4 showed a 100% infection rate in T. confusum larvae, while BbSA-5, BbSA6, BbSA-7, BbSA-8, and BbSA-9 had infection rates of 70%, 80%, 80%, 75%, and 95%, respectively. In terms of adult mortality rates, B. bassiana BbSA-4, BbSA-5, BbSA-6, BbSA-7, BbSA-8, and BbSA-9 had rates of 25%, 35%, 35%, 20%, 20%, and 40%, respectively. The research findings show that indigenous B. bassiana and M. anisopliae fungus isolates successfully eliminated T. confusum larvae, although their effectiveness against adults was limited. [ABSTRACT FROM AUTHOR]

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), is the most deleterious pests of palms worldwide, including date palms in the Kingdom of Saudi Arabia (KSA). An understanding of RPW diversity is crucial for designing management strategies of this pest. In this study, collections of RPW from date palm plantations were made in six known RPW-infected regions of KSA. The main objectives of the study were to characterize the RPW diversity in KSA using pronotal markings and cytochrome oxidase subunit I (COI) gene. The results showed that based on pronotal markings, 18 different color morphs of RPWs were found, while based on the COI gene, it could be separated into three main haplotypes. Pronotal marking and COI gene diversity revealed that the Riyadh and Eastern Regions were the major RPW diversity hotspots and the primary sources for subsequent RPW introductions into other regions of KSA. [ABSTRACT FROM AUTHOR]

The red palm weevil, Rhynchophorus ferrugineus (Oliv.) (Coleoptera: Curculionidae), is a highly damaging pest of palm trees worldwide. The infestation is highly concealed in nature. Hence, a highly sensitive and reliable early detection technique needs to be applied in the field for identification and treatment of the infested date palms to curtail further infestation. We have recently reported the differential proteomic analysis of the date palm stem tissues associated with the red palm weevil infestation. In this study, we examine the response of date palm infested with red palm weevil based on the leaf proteome expression changes detected using two-dimensional differential gel electrophoresis (2D-DIGE) followed by Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight (MALDI-TOF). We observed qualitative and quantitative proteome differences between the control and weevil-infested date palm samples. The red palm weevil infestation induced specific responses attributable to weevil feeding, relative to artificially wounded trees (which were used as a control). Differential proteomics led to the identification of 32 red palm weevil infestation-specific protein spots (P = 0.05 having ≥ 1.5-fold modulation) that were further subjected to mass spectrometer analysis for identification and characterization. Proteins involved in plant stress and plant defense, photosynthesis, carbohydrate utilization, and protein degradation were affected in infested plants. The differentially expressed red palm weevil infestation-specific peptides can be used as biomarkers for the identification of early infestation with this insect in date palm trees. Moreover, our study demonstrates the potential use of proteomic strategies in diagnosing phyto-infestation caused by insect pests, diseases, and perhaps even for variety selection. [ABSTRACT FROM AUTHOR]

A state of the art proteomic methodology using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI TOF) has been employed to characterize peptides modulated in the date palm stem subsequent to infestation with red palm weevil (RPW). Our analyses revealed 32 differentially expressed peptides associated with RPW infestation in date palm stem. To identify RPW infestation associated peptides (I), artificially wounded plants (W) were used as additional control beside uninfested plants, a conventional control (C). A constant unique pattern of differential expression in infested (I), wounded (W) stem samples compared to control (C) was observed. The upregulated proteins showed relative fold intensity in order of I > W and downregulated spots trend as W > I, a quite interesting pattern. This study also reveals that artificially wounding of date palm stem affects almost the same proteins as infestation; however, relative intensity is quite lower than in infested samples both in up and downregulated spots. All 32 differentially expressed spots were subjected to MALDI-TOF analysis for their identification and we were able to match 21 proteins in the already existing databases. Relatively significant modulated expression pattern of a number of peptides in infested plants predicts the possibility of developing a quick and reliable molecular methodology for detecting plants infested with date palm. [ABSTRACT FROM AUTHOR]

Differential proteomics is considered as one of the most powerful tools for evaluating relative expression of molecular moieties either in plants or animals. The present study focuses first on optimizing a rapid and sensitive protocol for the isolation of high quality protein to be used in two dimensional gel electrophoresis (2DE) from date palm samples, and then comparing differentially expressed peptides associated with red palm weevil (RPW) infestation of this plant using uninfested plants as control. Among the several methodologies we used for optimization, it was revealed that Phenol/ SDS extraction followed by methanolic ammonium acetate precipitation (designated as protocol 3 in this study) yielded high quality protein. Moreover, 2DE protein analysis demonstrated both qualitative and quantitative differences between control and infested date palm samples. Our differential proteomic methodologies showed 22 differential spots having modulation level ≥1.5 fold. Subsequently, these differentially expressed peptides were subjected to MALDI-TOF peptide mass fingerprinting analysis for their characterization. The 11 peptides identified through these methodologies fall into three major functional groups including stress/defense (5), photosynthesis (2), ion transport (1) related proteins and three with other functions. Our data revealed that proteins related to date palm defense or stress response were up-regulated in infested samples while the proteins involved in photosynthetic activities were down regulated. The present results indicated that RPW infestation of date palm plants induced molecular changes manifested through differential expression of proteins. Differentially expressed peptides besides increasing our understanding relevant to RPW infestation will help us in developing methodologies for early detection of RPW infestation beneficial for curbing this problem in economically important date palm trees. [ABSTRACT FROM AUTHOR]

Postharvest almond moth (Cadra cautella Walker; Lepidoptera: Pyralidae) infestation is one of the primary challenges for production of dates, Phoenix dactylifera L. (Arecaceae) cv. 'Khodari.' This study was a simulation of early almond moth infestations in uncontrolled storage conditions. It aimed to investigate the effects of low level almond moth infestations on the population growth of the moth, the damage to the dates, bacterial and fungal contamination, and the nutritional value of the dates. One, 2, and 3 pairs of male and female moths were introduced into 250 g Khodari date samples. Noninfested dates were used as controls. Each treatment was performed in 10 replicates. The results showed a more than 25-fold increase in the almond moth population and significant damage to the dates. The moth population in the 2 pair treatment was the highest. Moth infestation also increased microbial contamination by more than 3-fold compared with noninfested dates. The treatment of the 3 pairs of moths significantly increased the bacterial load more than 20-fold when compared to the control. The fungal contamination in the 2 and 3 pair treatments were more than 5-fold higher than that of the control. In contrast, the moth pairs did not significantly affect the sugar, protein, fiber, ash, or water contents of dates. The results suggest that infestation by a single pair of almond moths at the initial stage postharvest causes significant damage and contamina- tion in Khodari dates. [ABSTRACT FROM AUTHOR]