Black Leg Research Articles

Ten-Year Trends in Aerial Stem Rot Management: Evaluating Copper-Based Solutions for Sustainable Potato Cultivation

Aerial stem rot (ASR) is an important disease of potato worldwide and is predominantly caused by the soft rot bacteria Pectobacterium carotovorum. It differs from black leg (caused by P. atrosepticum) as it is found later in the season after row closure. The pathogen enters through wounds in the stem and expands outward leaving a distinct black lesion. Lesions spread down the stem as opposed to black leg lesions which spread up the stem from diseased tubers. Ten years of field trials were conducted using a susceptible variety in a randomized complete block design. Treatments consisted of different formulations of copper fungicides starting at row closure and continuing on a seven-day schedule until vine kill. Disease incidence and severity was rated visually, and results were used to calculate the Relative Area Under the Disease Progress Curve (RAUDPC), showing the rate of disease progress. Results showed that the RAUDPC was consistently higher in the untreated check compared to fungicide-treated plots, suggesting these products significantly reduced both disease incidence and severity. However, while the fungicides reduced disease, this did not always translate into higher yields. Nevertheless, factorial analysis of variance of yield by treatment showed significant differences in total yields with fungicide-treated plots outperforming the untreated check with yields at least 3 tonnes/ha higher. There have been few studies on the efficacy of copper fungicides for control of ASR. The findings of this ten-year study should provide growers with the data necessary to make informed decisions on the management of ASR.

Выявление патогенов картофеля с использованием различных методов диагностики

Abstract. Potato diseases have far reaching implications for the agricultural industry as they not only reduce productivity and quality of potato crop but also negatively affect the livelihood of farmers. The purpose of the studies detection and identification of potato phytopathogens by visual assessment, real time polymerase chain reaction (PCR) and molecular genetic screening for phytopathogen resistance genes. Methods. Visual evaluation of each potato variety for major fungal, viral and bacterial diseases was carried out during the period of full sprouting, at plant height of 15–20 cm and in the phase of full flowering. The percentage of plants affected by diseases in relation to the total number of inspected plants was calculated. Diagnosis of resistance of potato samples to diseases was carried out on the basis of PCR. DNA markers of phytopathogen resistance genes YES3-3A, RYSC3, Ry186, TG 689, Gro1-4-1, Gpa2-2, PVX were used for molecular screening of potato. Infection of samples by PCR-RV (real-time) was determined using reagent kits of Syntol LLC Potato Virus X and Potato Virus Y, Potato spindle tuber viroid-PB, Clavibacter michiganensis subsp. sepedonicus-PB, Dickeya spp-PB. Results. According to the results of visual evaluation, the absence of symptoms of wrinkle mosaic in 20% of hybrids, mottle mosaic in 40%, mosaic leaf curl in 96 %, leaf curl in 72 hybrids, black leg in 100%, phytophthorosis in 88% of hybrids, alternaria in 84 %, rhizoctoniosis in 96 % of hybrids were observed. According to the results of PCR-RV analysis in 21 samples detected virus Y. The scientific novelty consists in the diagnosis of potato viruses using traditional visual assessment with the use of molecular markers that allow to identify correlation relationship between trhis methods.

A novel genus of Pectobacterium bacteriophages display broad host range by targeting several species of Danish soft rot isolates

The bacterial diseases black leg and soft rot in potatoes cause heavy losses of potatoes worldwide. Bacteria within the genus Pectobacteriaceae are the causative agents of black leg and soft rot. The use of antibiotics in agriculture is heavily regulated and no other effective treatment currently exists, but bacteriophages (phages) have shown promise as potential biocontrol agents. In this study we isolated soft rot bacteria from potato tubers and plant tissue displaying soft rot or black leg symptoms collected in Danish fields. We then used the isolated bacterial strains as hosts for phage isolation. Using organic waste, we isolated phages targeting different species within Pectobacterium. Here we focus on seven of these phages representing a new genus primarily targeting P. brasiliense; phage Ymer, Amona, Sabo, Abuela, Koroua, Taid and Pappous. TEM image of phage Ymer showed siphovirus morphotype, and the proposed Ymer genus belongs to the class Caudoviricetes, with double-stranded DNA genomes varying from 39 kb to 43 kb. In silico host range prediction using a CRISPR-Cas spacer database suggested both P. brasiliense, P. polaris and P. versatile as natural hosts for phages within the proposed Ymer genus. A following host range experiment, using 47 bacterial isolates from Danish tubers and plants symptomatic with soft rot or black leg disease verified the in silico host range prediction, as the genus as a group were able to infect all three Pectobacterium species. Phages did, however, primarily target P. brasiliense isolates and displayed differences in host range even within the species level. Two of the phages were able to infect two or more Pectobacterium species. Despite no nucleotide similarity with any phages in the NCBI database, the proposed Ymer genus did share some similarity at the protein level, as well as gene synteny, with currently known phages. None of the phages encoded integrases or other genes typically associated with lysogeny. Similarly, no virulence factors nor antimicrobial resistance genes were found, and combined with their ability to infect several soft rot-causing Pectobacterium species from Danish fields, demonstrates their potential as biocontrol agents against soft rot and black leg diseases in potatoes.

The miracle transplantation of a black leg by the surgeon saints Cosmas and Damian.

The miracle transplantation of a black leg by the surgeon saints Cosmas and Damian.

Molecular characterization of Pectobacterium atrosepticum infecting potato and its management through chemicals.

Potato farming is a vital component of food security and the economic stability especially in the under developing countries but it faces many challenges in production, blackleg disease caused by Pectobacterium atrosepticum (Pa) is one of the main reason for damaging crop yield of the potato. Effective management strategies are essential to control these losses and to get sustainable potato crop yield. This study was focused on characterizing the Pa and the investigating new chemical options for its management. The research was involved a systematic survey across the three district of Punjab, Pakistan (Khanewal, Okara, and Multan) to collect samples exhibiting the black leg symptoms. These samples were analyzed in the laboratory where gram-negative bacteria were isolated and identified through biochemical and pathogenicity tests for Pa. DNA sequencing further confirmed these isolates of Pa strains. Six different chemicals were tested to control blackleg problem in both vitro and vivo at different concentrations. In vitro experiment, Cordate demonstrated the highest efficacy with a maximum inhibition zones of 17.139 mm, followed by Air One (13.778 mm), Profiler (10.167 mm), Blue Copper (7.7778 mm), Spot Fix (7.6689 mm), and Strider (7.0667 mm). In vivo, Cordate maintained its effectiveness with the lowest disease incidence of 14.76%, followed by Blue Copper (17.49%), Air One (16.98%), Spot Fix (20.67%), Profiler (21.45%), Strider (24.99%), and the control group (43.00%). The results highlight Cordate's potential as a most effective chemical against Pa, offering promising role for managing blackleg disease in potato and to improve overall productivity.

Two new species of <i>Aulacoscelis</i> Duponchel & Chevrolat 1842 from Mexico (Coleoptera: Orsodacnidae: Aulacoscelidinae)

Two new species of Aulacoscelis are described from the same locality (Guadalajara, Mexico): A. caroli n. sp. and A. nahuatl n. sp. With A. grandis Jacoby they form a group of taxa characteristic in the elytra completely spectrum orange in color, with shiny black head, thorax (at least in large part for A. grandis), legs and ventral parts. A. caroli n. sp. is characterized by a relatively small size, smooth pronotum, sides of pronotum sinuate proximally starting from nearly mid length, straight tibiae, straight and sharpened apex of aedeagus. A. nahuatl n. sp. is characterized by a relatively large size, with irregular surface of pronotum, sides of pronotum straight in their basal half, bent mesotibiae and sinuate apex of aedeagus.

The African Presence in Iberian Art*

The African presence in early modern Iberia increased with the emergence of the transatlantic slave trade following the discoveries of the Americas from the middle of the fifteenth century. This article focuses on the visual representation of Africans in the Kingdom of Portugal and the Spanish Kingdoms of Aragon and Castile until the seventeenth century. It focuses on the depiction of urban enslaved and liberated Africans in the main cities of Lisbon and Seville, in religious compositions, as the most popular Adoration of the Magi and the violent Castilian iconography of The Miracle of the Black Leg and in portraiture.

An Efficient Triplex TaqMan Quantitative PCR to Detect a Blackleg-Causing Lineage of Pectobacterium brasiliense in Potato Based on a Pangenome Analysis.

P. brasiliense is an important bacterial pathogen causing blackleg (BL) in potatoes. Nevertheless, P. brasiliense is often detected in seed lots that do not develop any of the typical blackleg symptoms in the potato crop when planted. Field bioassays identified that P. brasiliense strains can be categorized into two distinct classes, some able to cause blackleg symptoms and some unable to do it. A comparative pangenomic approach was performed on 116 P. brasiliense strains, of which 15 were characterized as BL-causing strains and 25 as non-causative. In a genetically homogeneous clade comprising all BL-causing P. brasiliense strains, two genes only present in the BL-causing strains were identified, one encoding a predicted lysozyme inhibitor Lprl (LZI) and one encoding a putative Toll/interleukin-1 receptor (TIR) domain-containing protein. TaqMan assays for the specific detection of BL-causing P. brasiliense were developed and integrated with the previously developed generic P. brasiliense assay into a triplex TaqMan assay. This simultaneous detection makes the scoring more efficient as only a single tube is needed, and it is more robust as BL-causing strains of P. brasiliense should be positive for all three assays. Individual P. brasiliense strains were found to be either positive for all three assays or only for the P. brasiliense assay. In potato samples, the mixed presence of BL-causing and not BL-causing P. brasiliense strains was observed as shown by the difference in Ct value of the TaqMan assays. However, upon extension of the number of strains, it became clear that in recent years additional BL-causing lineages of P. brasiliense were detected for which additional assays must be developed.

Chemical Identification of Secondary Metabolites from Rhizospheric Actinomycetes Using LC-MS Analysis: In Silico Antifungal Evaluation and Growth-Promoting Effects.

The rhizosphere is a rich source of actinomycetes which can produce several potential biologically active secondary metabolites. The principal goal for this research is to extract, purify, and characterize the bioactive secondary metabolites produced by three different strains of actinomycetes isolated from the rhizosphere of rosemary, black locust, and olive. The plant growth-promoting effect (PGPE) of the studied strains of actinomycetes on Ocimum basilicum L. (basil) and the disease-control effect on necrotic stem lesions of "black leg" caused by Fusarium tabacinum on basil were evaluated in silico. The cell-free culture filtrates from the studied actinomycetes isolates were evaluated in vitro for their antimicrobial activity against some common phytopathogens. The secondary metabolites obtained from the cell-free culture filtrates have been chemically characterized using high-resolution electrospray ionization of liquid-chromatography/mass-spectrometric detection (ESI-(HR)Orbitrap-MS). Results of the in silico trial showed that all studied isolates demonstrated PGPE on basil seedlings, improved some eco-physiological characteristics, and reduced the disease incidence of F. tabacinum. The extracted metabolites from the studied actinomycetes demonstrated antimicrobial activity in a Petri-plates assay. The chemical analysis revealed the presence of 20 different components. This research emphasizes how valuable the examined isolates are for producing bioactive compounds, indicating their putative antimicrobial activity and their potential employment as fungal biocontrol agents. In particular, the obtained results revealed the possibility of green synthesis of some important secondary metabolites, such as N-Acetyl-l-histidinol, Rhizocticin A, and Eponemycin, from actinomycetes. The bioactive metabolites may be successively used to develop novel bio-formulations for both crop protection and/or PGPE.

KARAKTERISTIK MORFOMETRIK KAMBING BOERKA PADA BERBAGAI TINGKATAN UMUR DI UPT. AGRI SCIENCE TECHNOPARK UNISLA

This study aims to identify the morphometric characteristics of male Boerka goats and female Boerka goats at different age levels as a basic step of selection in breeding and improving the genetic quality of goats. A total of 25 samples of Boerka goats, namely 10 male Boerka goats and 15 female Boerka goats were used to identify qualitative and qualitative traits at the age levels of 0-6 months, >6-12 months, and >12 months. The morphometric parameters observed consisted of qualitative characteristics, namely the diversity of coat colors, the diversity of horn shapes, the diversity of the color of the legs and the diversity of the front lines. While quantitative traits consist of body weight, height, body length, and chest circumference. The results of qualitative research found that Boerka goats had a dominant diversity of brown white fur color, short and small horns, black and white leg color, and a convex head shape. The average values ​​of body weight, height, body length, and chest circumference of male Boerka goats and female Boerka goats at various age levels were not significantly different except for chest circumference with age group > 12 months

Washed Clean

Washed Clean Ann Leamon (bio) Springtime on the Maine farm where I grew up meant melting. The smell of manure and mud mixed with the tang of smoke as maple sap boiled off to syrup. It meant lambing, too; my mother waking at two in the morning to check on the ewes. Most of them, dirty white skeins of unspun wool on skinny black legs, birthed their twins without trouble, even in the dirt-floored lean-to, but Granny, the matriarch—a scruffy, stubborn blend of unknown breeds—had triplets year after year. Sometimes the three could manage; alternatively, we bottle-fed the smallest, keeping it in a box behind the kitchen woodstove. In the dark March nights, often with snow or freezing rain, my mother pulled on her boots and jacket and checked on the sheep. Granny always lambed between the checks. One night during a fierce snowstorm, Granny lambed. In the harsh light of the two a.m. flashlight, Mom found two tiny figures, snuggled against the old ewe just as they should be. Maybe, this time, she’d only had the two. But at the morning feeding, under a drift of snow, we found the third, a cold scrap of pure white fluff. Oh, lamb of God. All creatures great and small. Remembering James Herriot, Mom put the small body in a bucket of warm water. It floated like a bar of Ivory soap. After five minutes, the lamb opened his eyes. [End Page 25] Ann Leamon Ann Leamon’s world includes venture capital research and creative writing. The sheep are gone, although she loves to watch them in the spring. In addition to writing a textbook and 150 cases for Harvard Business School, she has published in The Lyric, Hole in the Head Review, Live Nudes, Microlit Almanac, They Call Us…, and The Boston Globe. She holds degrees in German, Economics, and Poetry from Dalhousie, the University of Montana, and the Bennington Writing Seminars, respectively. She lives on the coast of Maine with her husband and a Corgi-Lab mix. Copyright © 2023 River Teeth

Long Day’s Journey Into Night

Long Day’s Journey Into Night

Research on the Effectiveness of Some Fungicides and Insecticides in Combating of Some Diseases and Pests of Rape in Cristian Commune - Brașov County

In Romanian agricultural production, autumn rape is in present an indispensable component of crop rotations because helps to maintain soil fertility and contributes to sustainable production therefore. Behavior against fungal diseases and insect pests for modern rape varieties represents an essential agronomic property. Rape pest and disease control is a priority to minimize quantitative and qualitative production losses. In plant protection, fungicides and insecticides must to be used only when is necessary and at optimal times and doses. The notations were made during the vegetation period of 2020, 2021 and 2022. Both fungicides applied (125 g/l azoxistrobin + 125 g/l difenoconazol and 125g/l fluopiram + 125 g/l protioconazol) showed high efficacy against alternaria, black leg and powdery mildew, and in the variants where both fungicides were applied, the highest efficacy was 98.8% against black leg and 98.9% anti powdery-mildew. The effectiveness of the two insecticides applied (240 g/l tiacloprid and 5% lambda-cihalotrin) varied between 87.2 and 97.3 against Ceutorhynchus napi, C. assimilis, Phyllotreta atra, Ph. nemorum and Brevicoryne brassicae.

ВЗАИМОДЕЙСТВИЕ ФАКТОРОВ ПРИ ОЦЕНКЕ СОРТОПОПУЛЯЦИЙ МОРКОВИ СТОЛОВОЙ НА УСТОЙЧИВОСТЬ К FUSARIUM И ALTERNARIA

At present more than 10,000 species of fungi associated with plants have been identified. A convincing proof of this is the widespread spread of fungal diseases on table carrots at all stages of plant development. Seedlings of Daucus carota L. are affected by pathogens of the genus Fusarium, causing a disease called «black leg», which leads to the death of infected seedlings. Adult plants are damaged by brown leaf spotting (pathogen Alternaria dauci (Kuhn), Grovers & Skolko), which contributes to premature death of the tops, which makes it difficult to use mechanization tools when harvesting root crops. With a high degree of plant damage in the root crops of table carrots, the content of carotene decreases by 24 % and sugars by 31 %. The degree of alternariasis spread by the end of the growing season reaches 90–100 %. These diseases of carrots are the most common and harmful in the Russian Federation and in the world. The creation of new highly productive and pathogen-resistant varieties and hybrids of carrots is complicated by the fact that the signs of resistance to fungi of the genera Alternaria and Fusarium in table carrots are controlled polygenically. Based on the above, the purpose of the research was: To identify the interaction of factors during field and laboratory experiments on varietal populations of table carrots to pathogens of the genera Fusarium and Alternaria. As a result of the work carried out, a high correlation coefficient (more than 0.70) was revealed between the assessment of mycosis resistance in field and laboratory experiments: spraying with a suspension of A. dauci leaf plate spores; infection of A. radicina and F.oxysporum seedlings; infection of disks with A. radicina and F. oxysporum mycelial blocks; evaluation of A. dauci and F. oxysporum culture fluid filtrate; assessment of resistance on artificial infectious backgrounds of A. radicina, A. dauci and F. oxysporum. A medium-susceptible group of varieties of table carrots has been identified, these are Vitamin 6, Losinoostrovskaya 13, Leander, Nuance, Queen of Autumn, Topaz F1, Star F1, Color F1, Irkut F1.

A Review on Potato Disease Detection and Classification by exploiting Deep Learning Techniques

The edible potato comes in fifth for human consumption and fourth among main food crops. Since it is a crop that is vegetative grown, many pests and disease can be passed along from one generation to the next. Crop diseases, which have a negative impact on food security as well as economic losses, have a significant impact on the production and quality of yields from potato crops. Thus, the application of unique and precise deep learning-based algorithms for disease detection and classification is highly required. Identifying weaknesses in agricultural products, particularly potatoes requires the use of machine vision and image processing techniques. Deep learning and image processing have been used in agriculture to classify and number of disease and pests affecting potatoes has grown, and study in this area is still continuing. The use of artificial intelligence and image processing in agriculture for the classification and identification of potato pests and disease has grown, and work in this area is still ongoing. Different deep learning techniques, such as VGG19, VGG16, Google Net, Alex Net, and convolution neural network methods, can be used to address the disease problem in potatoes. These methods also examined multiple classes of potato diseases as: Healthy, Black Leg, Black Scurf, Pink Rot, Common Scab, etc. Food safety could be seriously threatened by the spread of potato disease. In this article, deep learning techniques for early detection of potato disease are discussed.

Taxonomic revision of Montina (Hemiptera: Heteroptera: Reduviidae) from Colombia with description of three new species

The Neotropical assassin bug genus Montina Amyot & Serville, 1843 (Reduviidae: Harpactorinae) is revised for Colombia. Montina has not been adequately explored taxonomically, with its last described species published in 1867. It has ten valid species distributed in tropical areas of Central and South America, but none of them have been formally recorded from Colombia. We describe three new species, M. calarca Mejía-Soto & Forero sp. nov., M. gladiator Mejía-Soto & Forero sp. nov., M. tikuna Mejía-Soto & Forero sp. nov., and report seven species as new records for the country: M. confusa (Stål, 1859), M. distincta (Stål, 1859), M. fumosa (Stål, 1867), M. lobata Stål, 1859, M. ruficornis (Fabricius, 1803), M. scutellaris Stål, 1859, and M. testacea (Stål, 1859). Montina calarca sp. nov. is distinguished by the reddish coloration with black head and legs; densely setose pronotum; connexival margin rounded on segments 4, 5, and 6 without protuberances, connexivum black with a narrow red band on margin; and translucent yellow membrane with hyaline cells and darkened veins. Montina gladiator sp. nov. is distinguished by the red coloration, with black legs, scutellum, and abdomen; connexival margin 4–5 lobed, 6 straight, segments 2–4 with acute posterior process on each segment, connexivum dark brown to black with a narrow red band on its margin. Montina tikuna sp. nov. is distinguished by the reddish-brown coloration, with black scutellum and abdomen; connexival margin nearly straight, segments 2–4 with small posterior acute process, 5–6 with obtuse process, connexivum black; ventral laterotergites only with black scattered erect setae. New characters help delimit Montina and differentiate it from Ploeogaster Amyot & Serville, 1843, its most similar genus. For all species we provide a diagnosis, images, documentation of genitalia, and distribution maps. A key to all the species of Montina is provided.

Northernmost distribution of Indian brown mongoose (Herpestes fuscus)

The Indian brown mongoose, Herpestes fuscus is among the six species of mongoose found in India. The species can be distinguished from other species of mongoose by its dark brown fur, black legs and thick, furry and conical tail. Brown mongoose has a restricted and disjunct distribution, with two populations of the nominate H. f. fuscus in the Western Ghats (Karnataka and Kerala) in Southern India and three other subspecies along the western coast of Sri Lanka. In southern India, brown mongoose has been recorded in wet evergreen forests of the Western Ghats from altitudes ranging between 450 to over 2,000 m a.s.l. Recently it has been recorded from Tadoba-Andheri Tiger Reserve, about 160 km south of Pench, also in Maharashtra.

Plenodomus species infecting oilseed rape in Russia

The Phoma disease (Phoma stem canker, black leg, Phoma leaf spot) is one of the most harmful diseases of oilseed rape and other Brassicaceae in the world, particularly in Russia. The causal agents of this disease are Plenodomus biglobosus and Plenodomus lingam. Since 2005, a number subclades have been described within P. biglobosus and P. lingam (2 and 7, respectively). These subclades can be identified by multilocus sequence analysis. So far, biodiversity and geographic distribution of Plenodomus spp. infecting oilseed rape in Russia, have not been comprehensively analyzed. For this study, as many as 18 Plenodomus spp. isolates were obtained from the samples of stem canker and leaf spot of oilseed rape from four regions of Russia in 2004–2021. The aims of this study were to identify the isolates by phylogenetic analyses inferred from 3 gene sequences: nuclear ribosomal internal transcribed spacer, actin, and β-tubulin, and to assess pathogenicity of the isolates. The phylogenetic reconstructions revealed two well-supported monophyletic clades corresponding to the two species of the genus Plenodomus., P. lingam ‘brassicae’ and P. biglobosus ‘brassicae’.This paper provides robust phylogeny of the Plenodomus spp. clade, accompanied with the detailed description of morphological features of both species, and results of pathogenicity tests.

Scientific evidence of sustainable plant disease protection strategies for oilseed rape (Brassica napus) in Sweden: a systematic map

BackgroundOilseed rape (OSR; Brassica napus L.) is a highly valued crop for food, feed and industrial use. It is primarily grown in temperate climates, and over recent decades, its area of production and profitability have increased. Concurrently, several diseases negatively impact OSR production. Diseases caused by soil-borne pathogens, pose a risk of substantial yield loss since crop rotation schemes have become narrow as the time lapse between OSR crops in a field has been shortened. The aims of this paper were to provide an overview of plant protection measures available for OSR production and to identify knowledge gaps and areas where more research is needed.MethodsThis systematic map builds on a previously published protocol and follows the ROSES reporting standard. The search strategy was developed in collaboration with stakeholders and designed to cover available scientific evidence for OSR disease management in climate zones relevant for Scandinavian crop production (Dfc, Dfb, Cfb and Cfa in the Köppen-Geiger climate classification). Five scientific databases were used to identify peer-reviewed literature, complemented by additional searches performed in grey literature. Articles were screened at three stages: the title, abstract and full text. The eligible publications included studies of OSR crops, and all measures to control crop disease in agricultural fields were considered eligible interventions. The comparator was intervention and no intervention, and the yield per unit area, disease suppression or an increase in crop quality were determined to be outcomes of interventions. A basic assessment of the experimental design of each study was performed to assess its eligibility. All articles were coded based on the following categories: the location and climate zone, disease, pathogen, intervention and management method, outcome and study design. Articles not reporting original data but judged to be relevant (i.e., review papers, books and notes of registration of cultivars) were saved in a separate category called “books, reviews and reports”.Review findingsA total of 4633 articles were collected through systematic searches. After duplicates were removed, 3513 articles were included in the screening process. After screening at the title and abstract levels, 897 articles were evaluated at the full text level, and 118 articles comprised the studies that met the eligibility criteria of the systematic map. The country (Canada) and region (Europe) with the largest OSR crop production areas also contributed the highest number of articles. In total, 17 different diseases were reported, with black leg (syn. Phoma stem canker) being the most studied disease. Nineteen different intervention methods or management types were examined. Cultivar resistance and pesticide application were the most studied control measures.ConclusionWe report scientific studies on plant disease protection measures for OSR based on field trials where the results are intended to be directly implemented in crop production management. The map clearly provides an overview of research progress throughout the time period chosen, and it identifies knowledge gaps regarding important diseases where only a few studies have been published, for example, diseases caused by viruses.

Description of a new hoverfly species of the genus Ferdinandea and the female of Eumerus muratovi from Tajikistan (Diptera: Syrphidae: Eristalinae)

A new species of the genus Ferdinandea Rondani, 1844 and the unknown female of Eumerus muratovi Barkalov, 2020 are described. The new species F. volkovae sp. nov. differs from all Palaearctic species of the genus in the coloration of the face, the frons and mesonotum completely covered with grey pollen, black scape and pedicel, and the details of the male genitalia. The female of E. muratovi is similar to that of E. kozlovi Stackelberg, 1952, but differs in the completely black legs, larger size and presence of brown spot on the wing.