Raspberry (Rubus idaeus L.) is susceptible to aphid-borne viruses. We studied the incidence of four of them - black raspberry necrosis virus (BRNV), raspberry leaf mottle virus (RLMV), raspberry vein chlorosis virus (RVCV), and Rubus yellow net virus (RYNV) - in raspberry plants and aphids in and around Norwegian raspberry crops for three years (2019, 2021, and 2022). Most of the samples were from symptomatic plants. Applying RT-PCR, 274 leaf samples and 107 aphid samples were analyzed. All four viruses were found, but BRNV dominated: it was detected in 93% of the 178 leaf samples with virus and was the only virus that occurred more frequently as a single infection than in co-infections with the other viruses. The old cv. Veten had the highest virus incidence (97%) among the sampled plants, followed by uncultivated raspberry in the boundary vegetation (82%). All aphids identified were Amphorophora idaei and Aphis idaei. BRNV and/or RLMV was detected in 27% of the aphid samples. Notably, BRNV was detected in 30% of A. idaei samples, a species not known as a BRNV vector. In subsequent transmission experiments we found that although A. idaei can acquire BRNV within one hour, it did not transmit the virus to healthy raspberry plants. In contrast, Am. idaei, a known BRNV vector, was able to acquire the virus within one minute and transmit it within one hour of inoculation. Our study will improve the identification and management of BRNV.

• Keywords
• Rubus, Rubus yellow net virus, black raspberry necrosis virus, raspberry leaf mottle virus, raspberry vein chlorosis virus,
• Publication type
• Journal Article MeSH

The adoption of the European Green Deal will limit acaricide use in high value crops like raspberry, to be replaced by biological control and other alternative strategies. More basic knowledge on mites in such crops is then necessary, like species, density, and their role as vectors of plant diseases. This study had four aims, focusing on raspberry leaves at northern altitude: (1) identify mite species; (2) study mite population densities; (3) investigate mite intra-plant distribution; (4) investigate co-occurrence of phytophagous mites, raspberry leaf blotch disorder and raspberry leaf blotch virus (RLBV). Four sites in south-eastern Norway were sampled five times. Floricanes from different parts of the sites were collected, taking one leaf from each of the upper, middle, and bottom zones of the cane. Mites were extracted with a washing technique and processed for species identification and RLBV detection. Mites and leaves were tested for RLBV by reverse transcription polymerase chain reaction (RT-PCR) with virus-specific primers. Phytophagous mites, Phyllocoptes gracilis, Tetranychus urticae, and Neotetranychus rubi, and predatory mites, Anystis baccarum and Typhlodromus (Typhlodromus) pyri were identified. All phytophagous mites in cultivated raspberry preferred the upper zone of floricanes, while in non-cultivated raspberry, they preferred the middle zone. The presence of phytophagous mites did not lead to raspberry leaf blotch disorder during this study. RLBV was detected in 1.3% of the sampled plants, none of them with leaf blotch symptoms, and in 4.3% of P. gracilis samples, and in some spider mite samples, implying that Tetranychids could also be vectors of RLBV.

• Keywords
• Emaravirus idaeobati, Anystidae, Eriophyidae, Generalist predatory mites, Raspberry leaf blotch virus, Tetranychidae,
• MeSH
• Population Density * MeSH
• Plant Leaves MeSH
• Plant Diseases parasitology   MeSH
• Animal Distribution MeSH
• Mites * physiology   MeSH
• Rubus * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Norway MeSH

A novel negative-sense single-stranded RNA virus showing genetic similarity to viruses of the genus Rubodvirus has been found in raspberry plants in the Czech Republic and has tentatively been named raspberry rubodvirus 1 (RaRV1). Phylogenetic analysis confirmed its clustering within the group, albeit distantly related to other members. A screening of 679 plant and 168 arthropod samples from the Czech Republic and Norway revealed RaRV1 in 10 raspberry shrubs, one batch of Aphis idaei, and one individual of Orius minutus. Furthermore, a distinct isolate of this virus was found, sharing 95% amino acid identity in both the full nucleoprotein and partial sequence of the RNA-dependent RNA polymerase gene sequences, meeting the species demarcation criteria. This discovery marks the first reported instance of a rubodvirus infecting raspberry plants. Although transmission experiments under experimental conditions were unsuccessful, positive detection of the virus in some insects suggests their potential role as vectors for the virus.

• Keywords
• HTS, Rubus, aphids, raspberry, rubodvirus,
• MeSH
• Phylogeny * MeSH
• Negative-Sense RNA Viruses genetics   classification   isolation & purification   MeSH
• Plant Diseases * virology   MeSH
• RNA, Viral genetics   MeSH
• Rubus * virology   MeSH
• Sequence Analysis, DNA MeSH
• Cluster Analysis MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Norway MeSH
• Names of Substances
• RNA, Viral MeSH