A new gregarious parasitoid species, Microplitis idreesae (Hymenoptera, Braconidae, Microgastrinae) reared from Mythimna sp. (Lepidoptera, Noctuidae), with a key to the species of Microplitis in the Kingdom of Saudi Arabia

A new species of parasitoid wasp (Braconidae, Microgastrinae) from the kingdom of Saudi Arabia (KSA) is described, Microplitis idreesae sp. nov. The genus is reported for the first time in the Eastern province of the KSA. This is the first host-parasitoid association for Microplitis documented in the country. The new species attacks Mythimna Ochsenheimer (Lepidoptera, Noctuidae). Natural history information is provided such as the association of males with females, geographical location, possible food plants, and details of wasp cocoons. In addition, a fragment of the mitochondrial cytochrome b gene is presented. A taxonomic key to the species of Microplitis reported from the KSA is provided. Characters of this new species and its affinities with the three previous species described from the KSA and four of the closely related to Palaeartic species are also discussed

Molecular Detection of Begomoviruses Infecting Some Vegetable Crops in Saudi Arabia

Begomoviruses have a huge impact on crop production worldwide. Investigations of begomviruses in four vegetable crops namely cucumber, squash, tomato, and watermelon were conducted by visual symptoms and molecular analysis using PCR with universal primers for begomoviruses. Obtained sequencing results of the core Coat Protein confirmed the presence of three already reported begomoviral species. TYLCV was detected on tomato samples exhibiting leaf curling and yellowing. Squash and greenhouse-grown cucumber plants were infected with the Oman strain TYLCV-OM. Watermelon chlorotic stunt virus (WmCSV) isolates were detected in watermelon and greenhouse cucumbers. The begomoviral species ToLCPMV shared 99% identity with the Iranian isolates that are known to be very destructive. Integrated pest management should be implemented against whitefly (Bemisia tabaci) to prevent the spread of begomoviruses on vegetable crops.</jats:p

Molecular and ultrastucture studies in barley mild mosaic virus transmission by Polymixa graminis

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First Occurrence of Coffee Leaf Rust Caused by Hemileia vastatrix on Coffee in Saudi Arabia

Coffee leaf rust (CLR) is a major disease of Arabica coffee caused by the biotrophic fungus Hemileia vastatrix. Jazan region in Saudi Arabia has long been one of the last coffee-producing regions in the world free of this disease. In August 2023, CLR was initially observed in coffee plantations located in Fyfa district one of the main coffee-producing mountains of Jazan region. The source of the infection is unknown, however CLR could have entered Jazan from the nearest coffee-producing locations that haven the pathogen. During a scheduled survey in August 2023, symptoms were observed including yellowish-orange lesions that frequently combined to form chlorotic lesions and exhibited the powdery appearance of yellow uredospores on the abaxial surface of leaves. The uredospores and teliospores were microscopically examined and their morphology matched the previously published description for H. vastatrix. The identity of H. vastatrix specimens was further confirmed based on PCR amplification and sequencing of ITS, sharing a 99&ndash;100% identity with previously published sequences, as belonging to H. vastatrix. The pathogenicity of H. vastatrix specimens was investigated on Coffee arabica plants under growth chamber conditions, and all were pathogenic relative to control, with 100% of disease incidence, therefore fulfilling Koch&rsquo;s postulates. Based on our findings, this is the first documentation of H. vastatrix causing CLR in Saudi Arabia

Multi-Locus Phylogenetic Analysis Revealed the Association of Six Colletotrichum Species with Anthracnose Disease of Coffee (Coffea arabica L.) in Saudi Arabia

Several Colletotrichum species are able to cause anthracnose disease in coffee (Coffea arabica L.) and occur in all coffee production areas worldwide. A planned investigation of coffee plantations was carried out in Southwest Saudi Arabia in October, November, and December 2022. Various patterns of symptoms were observed in all 23 surveyed coffee plantations due to unknown causal agents. Isolation from symptomatic fresh samples was performed on a PDA medium supplemented with streptomycin sulfate (300 mg L&minus;1) and copper hydroxide (42.5 mg L&minus;1). Twenty-seven pure isolates of Colletotrichum-like fungi were obtained using a spore suspension method. The taxonomic placements of Colletotrichum-like fungi were performed based on the sequence dataset of multi-loci of internal transcribed spacer region rDNA (ITS), chitin synthase I (CHS-1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), &beta;-tubulin (TUB2), and partial mating type (Mat1&ndash;2) (ApMat) genes. The novel species are described in detail, including comprehensive morphological characteristics and colored illustrations. The pathogenicity of the isolated Colletotrichum species was assessed on detached coffee leaves as well as green and red fruit under laboratory conditions. The multi-locus phylogenetic analyses of the six-loci, ITS, ACT, CHS-1, TUB2, GAPDH and ApMat, revealed that 25 isolates were allocated within the C. gloeosporioides complex, while the remaining two isolates were assigned to the C. boninense complex. Six species were recognized, four of them, C. aeschynomenes, C. siamense, C. phyllanthi, and C. karstii, had been previously described. Based on molecular analyses and morphological examination comparisons, C. saudianum and C. coffeae-arabicae represent novel members within the C. gloeosporioides complex. Pathogenicity investigation confirmed that the Colletotrichum species could induce disease in coffee leaves as well as green and red fruits with variations. Based on the available literature and research, this is the first documentation for C. aeschynomenes, C. siamense, C. karstii, C. phyllanthi, C. saudianum, and C. coffeae-arabicae to cause anthracnose on coffee in Saudi Arabia