Summary Lecanosticta acicola causes brown spot needle blight (BSNB) of Pinus species. The pathogen occurs mostly in the Northern Hemisphere but has also been reported in Central America and Colombia. BSNB can lead to stunted growth and tree mortality, and has resulted in severe damage to pine plantations in the past. There have been increasingly frequent new reports of this pathogen in Europe and in North America during the course of the past 10 years. This is despite the fact that quarantine practices and eradication protocols are in place to prevent its spread. Taxonomy Kingdom Fungi; Phylum Ascomycota; Subphylum Pezizomycotina; Class Dothideomycetes; Subclass Dothideomycetidae; Order Capniodales; Family Mycosphaerellaceae; Genus Lecanosticta. Host range and distribution Lecanosticta spp. occur on various Pinus species and are found in North America, Central America, South America (Colombia), Europe as well as Asia. Disease symptoms Small yellow irregular spots appear on the infected pine needles that become brown over time. They can be surrounded by a yellow halo. These characteristic brown spots develop to form narrow brown bands that result in needle death from the tips down to the point of infection. Needles are prematurely shed, leaving bare branches with tufts of new needles at the branch tips. Infection is usually most severe in the lower parts of the trees and progresses upwards into the canopies. Useful websites The EPPO global database providing information on L. acicola (https://gd.eppo.int/taxon/SCIRAC) Reference genome of L. acicola available on GenBank (https://www.ncbi.nlm.nih.gov/genome/?term=Lecanosticta+acicola) JGI Gold Genome database information sheet of L. acicola sequenced genome (https://gold.jgi.doe.gov/organism?xml:id=Go0047147)

Purpose of review Within the discipline of invasion science, researchers studying different taxonomic groups have developed distinct ways of investigating the phenomenon of biological invasions. While there have been efforts to reconcile these differences, a lack of knowledge of diversity, biogeography and ecology hampers researchers seeking to understand invasive microorganisms, including invasive forest pathogens (IFPs).Recent findings Advances in molecular technologies such as gene and genome sequencing and metagenomics studies have increased the "visibility" of microorganisms, providing opportunities to better integrate forest pathology and invasion science. The two fields have much to gain from closer collaboration.Summary We propose a modified version of the Unified Framework for Biological Invasions to accommodate IFPs, recognizing the challenges and limitations, and suggest options for tackling these issues. We explore the pathways by which IFPs are transported, and in doing so highlight the need for the refinement of current pathway frameworks to better accommodate IFPs. With a clearer understanding of how microorganisms move around and the stages they pass through to become invasive, we hope that forest pathologists will better understand how and why invasions occur, and importantly, where, when and how invasions can be stopped or mitigated. We call for a broader incorporation of ecological and evolutionary concepts to address the complex challenges of identifying and managing IFPs.

The genus Calonectria accommodates many important pathogens of agricultural, horticultural and forestry crops, including Eucalyptus. During 2017 surveys of Eucalyptus diseases in Sabah, Malaysia, typical symptoms of Calonectria leaf blight were observed. A large number of Calonectria isolates were collected from diseased leaves and soils associated with symptomatic trees. The aim of this study was to identify and resolve the phylogenetic relationships between these isolates using morphological characters and DNA 1 sequence comparisons for six gene regions. From a collection of 73 isolates, eight species residing in three species complexes were identified. Among these, four undescribed species were characterized, and are named here as Ca. borneana, Ca. ladang, Ca. pseudomalesiana and Ca. tanah. Results of this study support the view that planted Eucalyptus in tropical and subtropical areas of the world represent niches remarkably rich in Calonectria spp. This also has implications for the management of diseases on these important trees.

The Coryneliaceae is a relatively small family of mainly pathogenic fungi occurring on a diversity of hosts with a wide global distribution. Members of the family are recognized by their black, upright and elongated ascomata. Historically, the taxonomy of this group was mainly based on morphological characters, but in more recent years DNA sequence data have resulted in new revisions. The genus Pewenomyces was recently described based on P. kutranfy, a canker pathogen on Araucaria araucana in Chile. Morphologically, this fungus resembles species in Caliciopsis and Hypsotheca. During the study in which Pewenomyces was described, three putative species were identified from the same host, two of which were observed only from cultures obtained by isolating from plant tissues. At the time of describing P. kutranfy, there was uncertainty regarding its novelty because two species of Caliciopsis (C. brevipes and C. cochlearis), a closely related genus in the Coryneliaceae, had previously also been described from the same host and location, but for which DNA sequence data were not available. In this study, phylogenetic analyses that were carried out for the three putative Pewenomyces species using sequences for seven gene regions, confirmed that they were distinct species.Herbarium specimens for the two Caliciopsis species were obtained for morphological comparisons and phylogenetic analyses. Although the holotypes for the two Caliciopsis species did not yield adequate DNA for a phylogenetic analysis, a detailed morphological study established that these species were clearly different from any of the Pewenomyces taxa. The three putative species are consequently described here as Pewenomyces lalenivora sp. nov., P. tapulicola sp. nov. and P. kalosus sp. nov.

The genus Calonectria includes many aggressive plant pathogens causing diseases on various agricultural crops as well as forestry and ornamental tree species. Some species have been accidentally introduced into new environments via international trade of putatively asymptomatic plant germplasm or contaminated soil, resulting in significant economic losses. This review provides an overview of the taxonomy, population biology, and pathology of Calonectria species, specifically emerging from contemporary studies that have relied on DNA‐based technologies. The growing importance of genomics in future research is highlighted. A life cycle is proposed for Calonectria species, aimed at improving our ability to manage diseases caused by these pathogens.