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Erysiphe is the largest genus of powdery mildews (PMs), a group of obligate plant pathogenic fungi. Exploration of biodiversity generally relies on regional surveys and our aim is to investigate the PMs in Taiwan. Collections of the fungi on five plant species around agricultural environments were subjected to morphological and molecular characterization, using both internal transcribed spacer (ITS) and β-tubulin gene (TUB2) regions for the phylogenetic analyses. Erysipheipomoeae comb. nov., a species able to infect Ipomoea obscura and I. aquatica demonstrated by pathogenicity tests, has been neotypified. The two buckwheat species, Fagopyrum esculentum and F. tataricum, are found to be hosts of E. aff. betae. These results suggest that hosts in some plant families can be infected by more than one Erysiphe pathogen, e.g., Convolvulaceae by E. ipomoeae and E. convolvuli and Polygonaceae by E. polygoni and E. aff. betae, respectively. In addition, phylogenetic analyses of PMs on Cardiospermum halicacabum and tomato belonging to the E. aquilegiae complex are allocated under E. neolycopersici comb. nov. This extends the potential host range of E. aquilegiae complex to the plant family Sapindaceae. We conclude that awareness of the host associations of PMs can potentially benefit crop disease management. [ABSTRACT FROM AUTHOR]

Increased antibiotic resistance has prompted the development of bacteriophage agents for a multitude of applications in agriculture, biotechnology, and medicine. A key factor in the choice of agents for these applications is the host range of a bacteriophage, i.e., the bacterial genera, species, and strains a bacteriophage is able to infect. Although experimental explorations of host ranges remain the gold standard, such investigations are inherently limited to a small number of viruses and bacteria amendable to cultivation. Here, we review recently developed bioinformatic tools that offer a promising and high-throughput alternative by computationally predicting the putative host ranges of bacteriophages, including those challenging to grow in laboratory environments.

Giant freshwater prawn, Macrobrachium rosenbergii , is an important economically aquaculture species widely farmed in tropical and subtropical areas of the world. Infectious precocity virus (IPV) is a virus that results in slow growth and sexual precocity of farmed M. rosenbergii and causes significant economic losses. A TaqMan probe Quantitative Real-time PCR (qPCR) and a nested PCR assay for IPV detection were established in this study. IPV was detected in crustaceans M. rosenbergii, M. nipponense , Procambarus clarkii , Litopenaeus vannamei , Penaeus monodon , and Oratosquilla oratoria and insect Anisops kuroiwae. On the contrary, it was not detected in fishes Misgurnus anguillicaudatus , Carassius auratus , Oreochromis mossambicus , Micropterus salmoides , and Pangasius bocourti ; crabs Eriocheir sinensis and Scylla paramamosain ; and malacostraca Charybdis feriatus with nested PCR in China. TaqMan probe qPCR was used to study the tissue tropism of IPV in M. rosenbergii. IPV mainly infected the brain, abdominal nerve, integument, and gill. From July 2019 to April 2021, 260 M. rosenbergii from IPV disease (IPVD) outbreak ponds were all IPV positive in nested PCR, and 40 M. rosenbergii from normal ponds without IPVD were all IPV negative in nested PCR. These results could be beneficial to the prevention and control of IPV infection. • The detection assays for infectious precocity virus (IPV) were established and evaluated. • Epidemiological investigation, and host ranges of IPV were studied. • IPV mainly infected the brain, abdominal nerve, integument, and gill of Macrobrachium rosenbergii. [ABSTRACT FROM AUTHOR]

Melons ( Cucumis melo L.) grown hydroponically in a greenhouse were heavily infested with powdery mildew. We isolated powdery mildew pathogens from the melon leaves and identified the isolate as Podosphaera xanthii KMP-6N, based on morphological characteristics and sequences of ribosomal DNA internal transcribed spacer (rDNA-ITS) regions. Host ranges of KMP-6N were determined by estimating the infectivity or pathogenicity after inoculating the conidia onto multiple plant species. The fungi caused severe powdery mildew symptoms on Cucurbitaceae plants, producing scattered conidia on conidiophores. The goal of this study was to observe KMP-6N conidiogenesis on melon leaves. The pathogen formed completely catenated conidiophores approximately 24 h from conidiophore erection to release of mature conidia. Six conidia were produced on the conidiophores and only the conidia at the apex reached maturity. The cycles of conidial release were repeated on melon leaves 14 to 18 times, at approximately 6-h intervals. In the final stage, conidia were released without causing growth and septation of generative cells. Conidiophores produced an average of 36 conidia during a 90-h period. In our study, the modes of conidiogenesis, lifetime of conidiophores and productivity of conidia on a conidiophore were described for powdery mildew fungi. [ABSTRACT FROM AUTHOR]

Recently, based on a limited morphological characterisation and partial 18S rRNA gene sequence, Jiang et al. (2019) described Trypanosoma micropteri Jiang, Lu, Du, Wang, Hu, Su et Li, 2019 as a new pathogen of farmed fish. Here we provide evidence based on the expanded sequence dataset, morphology and experimental infections that this trypanosome does not warrant the establishment as a new species, because it is conspecific with the long-term known Trypanosoma carassii Mitrophanow, 1883, a common haemoflagellate parasite of freshwater fish. The former taxon thus becomes a new junior synonym of T. carassii.

The article discusses the findings of a survey regarding Microgastrinae at the Yanacayu Biological Station in Napo Province, Ecuador. It summarizes Microgastrinae according to their host specialization and diversity. Microgastrinae composed of two hundred rearing of caterpillars were distributed in 14 genera, thus its eleven hyperparasitoids were also summarized. Moreover, the results are compared to those recovered by surveys in Costa Rica and in other countries.

Abstract: Partial ß-tubulin 1 sequence data were obtained for 80 taxa of Pucciniaceae, with hosts from 33 angiosperm families, covering all major ordinal groups in the Angiosperm Phylogeny Group classification. As in previous studies, most species of Puccinia and Uromyces fell into two main clades (I and II), with P. glechomatis and P. psidii excluded from Pucciniaceae. Results suggest two processes; a coevolution of and hosts in each clade, as well as associated frequent jumps to ecologically close, but taxonomically distant, hosts. Clade I contained all rusts on Cyperaceae and Juncaceae, and most rusts on host orders from rosids to euasterids II. Clade II contained all rusts on Poaceae, and most on host orders from monocots to core eudicots. In both main clades, several well-supported subclades were identified. The grouping in clade I, subclade E of rusts of Cyperaceae and Asteraceae and, in particular, of an Australian isolate of P. dioicae with rusts on Australian families of Asterales, suggested a local radiation, and supported the coevolutionary relationship between rusts on these two families seen with a different range of asteraceous rusts in the Northern Hemisphere. In clade I, two clades contained only rusts of Asteraceae and Fabaceae, respectively, and in clade II, subclade F contained only rusts of pooid hosts. Rusts on non-pooid hosts were separated from them in subclade G. Other subclades contained a range of rusts on distantly related angiosperm families. Urediniospore morphology was often, but not always, correlated with the molecular phylogeny. Most rusts with urediniospores having few (1–5) equatorial germ pores were in clade I, whereas most with spores having several (5–14) scattered pores were in clade II. The distribution of telial host families on the ß-tubulin rust phylogeny was not random. Aecial hosts of heteroecious rusts played an important role in the evolutionary process. Possible examples of host jumps were seen in rusts on Geraniaceae, Polygonaceae, and Apiaceae. Despite such jumps obscuring past host associations, possible ancestral hosts were identified by the pattern of host distribution at higher taxonomic levels along the ß-tubulin phylogeny. Results suggest that clade I diverged with Cyperaceae, Juncaceae, and the more advanced core eudicot orders (rosids and asterids), whereas clade II diversified with earlier angiosperm groups, such as monocots, Poaceae, and Ranunculales. Qualified support was given to the hypothesis that rusts can reveal taxonomic relationships between their hosts, at genus, family, and ordinal levels. [Copyright &y& Elsevier]

• To advance understanding of the contribution of ectomycorrhizal (ECM) fungi to tree successional processes, natural establishment patterns of secondary colonizing hosts and their ECM fungal communities were investigated with special reference to pioneer hosts. • In the volcanic desert on Mount Fuji, Japan, vegetation is sparsely distributed, resembling islands in a sea of scoria. Of 509 vegetation islands in the research area, 161 contained Salix reinii ( Salix), the first colonizing ECM host species. The spatial coincidence between secondary colonizing timber species and Salix was analysed, and ECM fungal communities were studied using molecular identification methods. • I found 39 and 26 individuals of Betula ermanii and Larix kaempferi, respectively. Without exception, these individuals were all accompanied by Salix. The ECM fungal communities of these timber species showed high similarity to that of Salix and were dominated by generalists that were compatible with two or more plant families. • In this desert, available ECM propagules are limited. Pioneer Salix may contribute to tree succession by providing adjacent late colonizers with compatible ECM fungal symbionts. [ABSTRACT FROM AUTHOR]

Increased antibiotic resistance has prompted the development of bacteriophage agents for a multitude of applications in agriculture, biotechnology, and medicine. A key factor in the choice of agents for these applications is the host range of a bacteriophage, i.e., the bacterial genera, species, and strains a bacteriophage is able to infect. Although experimental explorations of host ranges remain the gold standard, such investigations are inherently limited to a small number of viruses and bacteria amendable to cultivation. Here, we review recently developed bioinformatic tools that offer a promising and high-throughput alternative by computationally predicting the putative host ranges of bacteriophages, including those challenging to grow in laboratory environments. [ABSTRACT FROM AUTHOR]

A nematological survey was carried out in a forest tree nursery in Andujar, southern Spain. Meloidogyne arenaria was found in soil and roots samples from Acacia sp., Biota sp., Juglans regia, Pinus spp., Salix babilonica and Sophora japonica. Pratylenchus vulnus was found in Acacia sp., Cupressus macrocarpa, Juglans regia, Ligustrum japonica, Morus sp., Pinus spp., Populus sp., Salix babilonica and Ulmus pumila. Helicotylenchus sp., Xiphinema americanum and Tylenchorhynchus sp. were found in all the plant species planted in the nursery. Paratylenchus sp., Criconemella sp. and Zygotylenchus guevarai host ranges are also given. The influence of soil storage on the recovery of M. arenaria was studied. At storage temperatures similar to those of the nursery (10-15°C), densities of M. arenaria in soil increased until the sixth week after sampling and were then maintained until the thirteenth week of storage. Incubation temperatures below 16°C during the migration of nematodes through a cottonwool filter, reduced the number of M. arenaria juveniles recovered after 15 h, but increasing migration time up to 39 h could counterbalance this reduction. Pflanzenparasitare Nematoden aus einer sudspanischen Forstbaumschulemit einigen Bemerkungen uber den Einfluss der Probenlagerung auf den quantitativen Nachweis von Meloidogyne arenaria - In einer Forstbaumschule in Andujar, Sudspanien, wurde eine nematologische Untersuchung durchgefuhrt. Meloidogyne arenaria wurde in Boden- und Wurzelproben von Acacia sp., Biota sp., Juglans regia, Pinus spp., Salix babilonica und Sophora japonica gefunden. Pratylenchus vulnus konnte an Acacia sp., Cupressus macrocarpa, Juglans regia, Ligustrum japonica, Morus sp., Pinus spp., Populus sp., Salix babilonica und Ulmus pumila nachgewiesen werden. Helicotylenchus sp., Xiphinema americanum und Tylenchorhynchus sp. wurden an allen Pflanzenarten gefunden, die in der Baumschule angebaut wurden. Ferner werden die Wirtspflanzen von Paratylenchus sp., Criconemella sp. und Zygotylenchus guevarai genannt. Dann wurde auch der Einfluss der Probelagerung auf den Nachweis von M. arenaria untersucht. Bei Lagerungstemperaturen von 10-15°C, die ahnlich waren wie die in der Baumschule, nahmen die Dichten von M. arenaria bis zur sechsten Woche nach der Probenahme zu und hielten sich dann bis zur 13. Woche der Lagerung. Temperaturen unter 16°C wahrend der Wanderung durch ein Baumwollwattefilter verminderten die Anzahl der nach 15h wiedergefundenen Juvenilen, doch konnte eine Verlangerung der Wanderzeit auf 39h diese Verminderung ausgleichen. [ABSTRACT FROM AUTHOR]

The genera of the insect parasitic nematode family Mermithidae axe reviewed, and 16 of them axe redescribed and illustrated. Information is given on methods of rearing adult mermithid specimens and on host specificity. The four types of merrnithid life cycles axe described in detail. One figure shows the variety of insects parasitized by merrnithids and the location and size of the nematode within the insect. Several mermithid eggs are illustrated, and their usefulness in identification is discussed.Taxonomically, the primary emphasis is on the adult stages of the merrnithJds with larval and egg characteristics supplementaxy. An emended family diagnosis is given. Merrnis subnigrescens is considered a synonym of M. nigrescens, and M. tahitiensis is synonymized with M. mirabilis. Hydromermis contorta is accepted, leaving the genus Paramermis in an uncertain position. Study of the Steiner collections of Limnornermis bathybia indicates that Limnornerrnis is accepted as a valid genus. The adults of Agamermis decaudata are descried and illustrated for the first time. The genus Gastromermis is limited to the long single-spiculed forms, as it is now apparent that five or more genera have ventrally shifted mouth orifices. Amphirnermis tinyi n. sp. is described from damselflies from Louisiana. The genus Lanceimermis is accepted, and three species in this genus are illustrated. The taxon Reesimermis nielseni has been accepted for this important parasite of more than 20 mosquito species. This nematode previously has been referred to as Romanomermis sp. Romanomermis iyengari is transferred to the genus Reesirnermis. Diximermis peterseni n. gen., n. sp., from anopheline mosquitoes, is described and iUustrated. The adults of Agamomermis culicis which parasitize Aedes sollicitans, are described for the first time, and the species placed in a new genus, Perutilimermis. The new genus Neornesornermis is proposed for Mesomermis flumenalis Welch, 1962. Several problems on mermithid morphology and taxonomy are discussed. Type material is established for some of the taxa.