In 2018–2019, FGBU “VNIIKR” prepared pest risk ana-lyses on agents of bacterial diseases included in the species complex Ralstonia solanacearum sensu lato. This species complex is included in the lists of the European and Mediterranean Plant Protection Organization (EPPO) and the European Union (EU) and reclassified in 2018 into 3 different species: R. solanacearum (А2), R. pseudo-solanacearum (А2) and R. syzygii (А1). In the process of preparing pest risk analyses, the taxonomic position of these species was studied, the collection, synthesis and analysis of data on their geographical distribution, phytosanitary status, host plants in the countries of distribution, biological characteristics, methods of detection and identification, pathways of these species, as well as their harmfulness, including in the economic dimension. According to the results of studies of the biology of the considered species, analysis of conditions favorable for the introduction and adaptation of pests, as well as their potential harmfulness, their phytosanitary risk for the territory of the Russian Federation was determined. It has been established that all considered species meet the criteria of quarantine organisms and can spread on the territory of the Russian Federation, causing significant damage to crops.

The article studies phomoid fungal pathogens associated with growing potatoes in Moscow Oblast and Leningrad Oblast identified in the period 2019–2020. Biological characteristics of pycnidial fungi and peculiarities of infestation symptom are presented, diagnostically significant cultural and morphological characters are described. As a result of the research, representatives of the genera Didymella, Neoascochyta, Phoma, Boeremia were identified from pycnidial fungi on diseased potato leaves. During the growing season, the dominant position among non-pycnidial fungi in 80% of the studied samples taken in Moscow Oblast was formed by species of the genus Alternaria. The fungus Boeremia foveata (Foister) Aveskamp, Gruyter & Verkley was isolated in a single case during a survey of potato plantings in the Pushkin district of St. Petersburg. The studied plants also contained species uncharacteristic for potatoes: from the affected leaves, the species Neoascochyta exitialis (Morini) Q. Chen & L. Cai и Didymella pinodella (L.K. Jones) Q. Chen & L. Cai were isolated once. As a result of the research, 10 species of phomoid pathogenic fungi were isolated and identified. The obtained isolates were deposited in the mycological collection of the FGBU “VNIIKR” to study the morphological features of the complex of potato micromycetes, the presence of which is possible together with quarantine pests.

The agent of the bacterial pea blight, Pseudomonas syringae pv. pisi (Sackett) Young et al. (P. s. pv. pisi), is a main phytopathogen of pea (Pisum sativum L.). National Plant Protection Organizations (NPPOs) require reliable techniques to confirm the absence of the bacterial blight agent. The aim of this work is to study the possibility of applying a pathogenicity test for the diagnosis of the bacterial pea blight agent. During the approbation of the test, we used pea plants of the Pioner variety, strain P. s. pv. pisi CFBP 2105, “Proba-GS” kit produced by LLC “AgroDiagnostika” (Russia), and the primers AN7F/AN7R (Qing Ch. et al., 2016). After preliminary tests, the proposed test for pathogenicity can be used to determine the virulence of the isolate, and can also be proposed as one of the additional confirmatory methods for identifying a phytopathogen in a test sample when developing guidelines for detecting and identifying the causative agent of the bacterial pea blight.

Peach latent mosaic viroid (PLMVd) is a quarantine pest included in the Common List of Quarantine Objects of the Eurasian Economic Union, the list of quarantine pests absent in the Eurasian Economic Union.

PLMVd affects stone fruit crops, causing significant yield losses. Methods for the detection and identification of this pathogen in the Russian Federation were developed by the specialists of FGBU “VNIIKR” in 2015–2018.

The article presents the results of testing and valid ation of several pairs of species-specific primers used in world practice for the diagnosis of PLMVd by the polymerase chain reaction (PCR) method, as well as the results of experiments with primers developed by the authors.

The article presents the results of studying the insects feeding on quarantine weeds of Cuscuta spp. (Cuscutaceae). The research was conducted by FGBU “VNIIKR” specialists in the Russian Federation and some neighboring countries from the late 1980s to the early 2000s. The list of the detected on Cuscuta spp. and identified phytophages includes 26 insect species of the orders Homoptera, Heteroptera, Lepidoptera, Coleoptera and Diptera. The biology of some phytophagous species and some of their parasites of Hymenoptera order has been studied. Detailed data on the biology of the most significant phytophages, Smicronyx genus snout and bark beetles and Melanagromyza cuscutae, as well as their effect on Cuscutaceae have been given. Conclusions have been drawn about the insignificant regulatory effect of the identified phytophages on Cuscutaceae populations.