Plant Protection News (Vestnik Zashchity Rasteniy)

Fungicides for protection against Oomycetes

2026-10-01T15:08:45+00:00

Oomycetes are a large group of heterotrophic organisms that evolutionarily differ from true fungi. They can be either free-living or parasitic. Among the parasites, the causal agents of agricultural plant diseases are of great economic importance. Oomycetes cause devastating diseases such as potato late blight, downy mildew of grapes, vegetables, and cruciferous crops. They also infect the roots of many agricultural plants, causing blackleg and root rots. The severe damage caused by these diseases has driven the development of various chemical fungicides aimed at protecting crops against oomycetes. However, given the evolutionary differences between oomycetes and true fungi, some fungicides are not effective against oomycetes. This paper provides a review of the chemical classes of fungicides used for protection against Oomycota, their modes of action, and their activity spectra.

Assortment of herbicides to control Johnsongrass (Aleppo grass)

2026-10-01T15:08:45+00:00

Literature data are analyzed concerning prevalence, control methods and herbicide assortment against Johnsongrass in Russia and worldwide. Sorghum halepense is a noxious weed threatening many agricultural crops, including corn, soybean, sunflower, cotton, and sugarcane. In Northern Hemisphere, with climate warming, its area widens to higher latitudes Reproduction with seeds and rhizomes facilitates its high invasiveness. Johnsongrass management systems should be integrate agronomic, mechanical, and chemical methods (emphasizing the latter). Herbicide assortment against S. halepense is extensive, comprising dozens of active ingredients with different action mechanisms. In Russia, acetyl-CoA carboxylase inhibitors based on clethodim, sethoxydim, quizalofop-P-tefuryl, fluazifop-P-butyl, and propaquizafop, and acetolactate synthase inhibitors based on nicosulfuron, rimsulfuron, imazethapyr, and imazapyr are most common. Resistant weed populations are identified worldwide. First glyphosate resistance case is recorded in Europe. To improve control measures, biological methods and novel action mechanisms of herbicides should be considered.

Virulence monitoring of the northwestern population of Puccinia triticina in 2023-2025

2026-10-01T15:08:44+00:00

Leaf rust, caused by Puccinia triticina, is a widespread disease of wheat in all regions of Russia, including the North-West. Long-term population-genetic studies of the pathogen make it possible to assess the dynamics of pathogen virulence variability and adjust breeding for resistance strategies. The work aimed to monitor the virulence and race composition of the northwestern population of P. triticina in 2023–2025 and to assess its long–term variability dynamics (2001–2025). High effectiveness of genes Lr9, Lr19, Lr25, Lr28, Lr29, Lr41 (=Lr39), Lr42, Lr47, Lr50, Lr51, Lr53 and Lr57 in the North-West is shown. In 2024–2025, pathogen isolates virulent to carriers of the previously highly effective Lr24 gene were found. In total, 17 phenotypes (races) were identified in the northwestern population in 2023–2025, and only four of them were recorded in 2000–2023. The ong-term variability of the Northwestern population mainly affects the virulence frequency variation of the pathogen to Thatcher lineages by genes Lr2a, Lr2b, Lr2c and Lr15. It decreased significantly in the 2020s. The northwestern population showed its stable consistent variability in 2001–2025. The 2001–2010 populations differed moderately from 2012–2019 and more significantly from 2020–2024. The 2025 pathogen collection was significantly different from those analyzed previously. Additionally, P. triticina collected on wheatgrass in 2025 showed high similarity of virulence to the samples from soft wheat. This confirms that wheatgrass may serve as a reservoir of leaf rust infection for soft wheat crops in the Northwest and contribute to the diversity of the regional pathogen population.

Fungicidal protection of winter wheat against the fungus Pyrenophora tritici-repentis

2026-10-01T15:08:46+00:00

The most widely used approach for controlling plant diseases, including tan spot of wheat (caused by Pyrenophora tritici-repentis), is the application of fungicides. The objective of this study was to evaluate the efficacy of biological fungicides in suppressing the development of P. tritici-repentis both in vitro and under field conditions, as well as to assess their compatibility with highly effective synthetic fungicides. Field assessments revealed that the biological effectiveness of microbiological preparations ranged from 38 % to 57 %, whereas that of chemical preparations ranged from 56 % to 98 %. In vitro inhibitory activity of the microbiological preparations against the pathogen was high, varying between 61 % and 72 %. Compatibility testing of biological and synthetic fungicides demonstrated that Pseudobacterin-3, (based on a Pseudomonas strain) was compatible with all tested chemical products except Magnello (difenoconazole, 100 g/l and tebuconazole, 250 g/l). Preparations based on Bacillus spp. exhibited variable compatibility with synthetic fungicides. Among these, Fitosporin-M, showed compatibility with the maximum number of chemicals (11 out of 14), while Orgamica C, was compatible with eight preparations. In contrast, microbial preparations based on Trichoderma strains did not show compatibility with any of the synthetic fungicides tested. These findings may be useful for the development of effective integrated pest management strategies against tan spot of wheat.

Molecular-genetic characteristics of gall-forming aphids Pemphigus spp. – the pests of poplars in Yenisei Siberia

2026-10-01T15:08:43+00:00

Pemphigus aphids (Hemiptera: Aphididae: Pemphigini) are gall-forming pests of poplars and agricultural crops. Morphological variability and cryptic species hinder taxonomic identification and range assessment. The molecular genetics of Palearctic species remain poorly understood, and no such studies have been conducted for Siberian representatives. Our pioneer study presents the results of DNA barcoding and analysis of genetic variability of four species (Pemphigus bursarius, P. matsumurai, P. passeki, P. populi) collected in Krasnoyarsk Krai and the Republic of Khakassia and identified by morphology. Holarctic species P. bursarius demonstrated high intraspecific variability (2.93 %) in COI mtDNA gene. The Siberian specimens of this species from black poplar (Pop. nigra) were genetically close to the Canadian population. A specimen from the Republic of Khakassia from laurel poplar (Pop. laurifolia) showed a genetic distance of 5.2 % from P. bursarius from Pop. nigra, highlighting the presence of a distant lineage. The Siberian specimen of P. matsumurai grouped with Chinese specimens of the same species and with specimens of P. sinobursarius stored in GenBank (the genetic distance varied from 0.46 to 1.04 %), not allowing to split these species using DNA barcoding. For the first time, DNA barcodes of P. populi and P. passeki have been obtained, which can serve as reference sequences for species identification. This study lays the ground for building molecular genetic libraries to study the phylogenetics and phylogeography of Pemphigus spp. in Siberia, and for developing reference DNA barcodes enabling precise identification and analysis of invasive processes in pest species.

Effectiveness of acaricides in the control of the mite Blattisocius tarsalis in the mass rearing technology of the Angoumois grain moth Sitotroga cerealella

2026-10-02T10:38:58+00:00

Eggs of Sitotroga cerealella are widely used as feed for the production of entomophagous insects. Predatory mite Blattisocius tarsalis inhabits the production facilities, damages eggs and negatively impacts moth development. This reduces the effectiveness of breeding technologies using grain moth eggs, a natural substitute for natural food. The specific problem of predatory mite control in biotechnological production is that the product must kill the mites without adversely affecting the main product – grain moth eggs. For this reason, the search for modern acaricides for the control of B. tarsalis in S. cerealella egg production has arisen. The efficacy of modern acaricides against B. tarsalis was assessed in laboratory experiments: Vertimek, EC (18 g/l); Ortus, SC (50 g/l); Sanmite, EC (150 g/l) and Floramite, SC (240 g/l). The greatest toxic effect was obtained with pyridaben (Sanmite, EC). The preparation at a concentration of 0.2 % not only caused 100 % mortality of ticks within the first 24 hours after application, but was also virtually safe for S. cerealella larvae hatching from treated eggs. In biotechnological production conditions, it is advisable to use flat, sealable plastic containers, the outer and inner surfaces of which are treated with an acaricide. After the working solution has dried, a thin layer of grain moth eggs, infested with mites and previously immobilized in a household refrigerator, is sprinkled into the solution and exposed for 1–2 days. The use of an acaricide should complement the preventive and sanitary measures taken when producing grain moth eggs.

Study of biological characteristics and development of methods for laboratory rearing of the parasitoid Dibrachys cavus (Hymenoptera: Pteromalidae)

2026-10-01T15:08:42+00:00

The primary objective of a living collection of entomoacariphagous arthropods is to preserve species biodiversity and their gene pool for reproduction under natural and laboratory conditions. The aim of this research was to replenish the bioresource collection of the Federal State Budgetary Scientific Institution «Federal Research Center of Biological Plant Protection» with the parasitoid hymenopteran Dibrachys cavus, as well as to study its biological characteristics, identify optimal rearing conditions, and investigate its trophic specialization. In 2023, adult D. cavus were collected in vineyards in the Temryuk District of Krasnodar Area. Optimal rearing and storage conditions were determined, and the insect host selected were the larvae of the greater wax moth Galleria mellonella. Storage of D. cavus at 15 °C (achieving metabolic slowdown) and 4 °C (development arrest) for 15 and 25 days at the adult stage did not negatively affect its developmental parameters. Under laboratory conditions, D. cavus effectively parasitized the larvae and pupae of the Eeuropean grapevine moth Lobesia botrana, the green oak tortrix Tortrix viridana, the yellow rose tortrix Acleris bergmanniana and the codling moth Cydia pomonella.

Toxicity of insecticides for the diamondback moth Plutella xylostella in the northwestern region of Russia

2026-10-06T13:01:21+00:00

Development of multiple resistance in local populations of the cabbage moth Plutella xylostella to insecticides from different chemical classes was revealed in Leningrad Region in 2023–2024. This led to a decrease in the biological efficacy of the most widely used lambda-cyhalothrin and deltamethrin formulations, as well as some mixed formulations containing lambda-cyhalothrin and alpha-cypermethrin on white cabbage in the Tosnensky and Pushkinsky districts. On both crops, an initial stage of resistance development in the cabbage moth has been detected to the organophosphate malathion, the oxadiazine indoxacarb, the diamides cyanotranilyprol and flubendiamide, and on white cabbage in the Tosnensky district, to the carbamate methomyl, which complicates the protection system. To prevent further development of this negative phenomenon, it is necessary to discontinue the use of both pyrethroids and corresponding combined preparations on cabbage and rapeseed. Insecticide rotation schemes for controlling the cabbage moth should be developed for a particular field exploiting chemicals from new chemical classesб accompanied with regular monitoring of pest sensitivity in order to promptly exclude preparations which lose their efficacy.

Xylophagous insect pests of Scots pine in a ribbon forest weakened by defoliation and ground fire in the south of the Altai Area

2026-10-01T15:08:42+00:00

The results of a pilot study of xylophagous insects in a ribbon pine forest, weakened by pine tree lappet moth Dendrolimus pini and ground fire, in the southern Altai Area are presented here. In June–July 2025, overall, 447 specimens from 17 species and three families (Cerambycidae, Curculionidae, and Buprestidae) were captured in two pheromone traps. The pine sawyer beetle Monochamus galloprovincialis and the six-toothed bark beetle Ips sexdentatus were dominant (in total up to 68 % of catches). These insects, along with the bark beetle Ips acuminatus, the weevils Pissodes piniphilus and Hylobius abietis, and the jewel beetles Phaenops cyanea and Buprestis haemorrhoidalis, are economically significant species. The assessment of the composition and abundance of xylophages in the catches is provided, which can serve as a basis for further monitoring and optimization of forest protection measures in the region.

Variability of Rhopalosiphum padi (Hemiptera, Aphididae) Russian populations in virulence to wheat varieties

2026-10-01T15:08:41+00:00

The bird cherry-oat aphid Rhopalosiphum padi interactions with wheat genotypes were analyzed. Antibiosis parameters (duration of aphid preimaginal development and female fecundity) were assessed for resistant (Delfi 400) and susceptible (Leningradskaya 97) varieties. Insect clones isolated from the populations of northwestern Russia, Nizhny Novgorod, Krasnodar, and Dagestan, were exploited. In 2020, Delfi 400 exhibited distinct antibiosis against clones from the northwestern population, and in 2022, against all clones from the four aphid populations. In 2021, the resistance was detected against the two Krasnodar clones and one clone from the northwestern population. Ten clones reproduced equally on both varieties, while one of the Dagestan clones developed faster and was more fecund on Delfi 400, indicating a differential insect-plant interaction. After prolonged reproduction of Rh. padi on Delfi 400 in laboratory, antibiosis expression was changed suggesting a mutation or long-term modification in the aphid, which suppressed the effect of wheat resistance genes.