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Gall‐forming hymenopterans of Eucalyptus species are highly successful invaders causing significant damage in non‐native plantation forests. To date, at least 16 of these species have been recorded as invasive eucalypt gall formers, of which less than half are known from Australia where they are thought to be native. About 80% of the species have become invasive only in the last two decades, <10%, of which were known from Australia beforehand.Two species, Leptocybe invasa and Ophelimus maskelli are global invaders that have become established in 43 and 23 countries, respectively, since 2000. They belong to a large number of wasps that cause similar damage and that could become invasive in the future.The problem of identification is exacerbated by the fact that many species lack taxonomic descriptions; over 80% of the invasive eucalypt gall wasps were first described from their invasive range. The small number of taxonomists able to identify these insects slows accurate diagnoses. Even when initial identifications have been made, these may be confused with morphologically similar but distinct cryptic species, which may differ in their host range and natural enemy interactions.Furthermore, detailed information regarding their biology and native distribution is typically sparse or unknown. This lack of information delays the initiation of management actions because breeding for resistance and biological control requires accurate identification of the target pest.The gall‐forming hymenopterans associated with Eucalyptus represent an important group on which to focus the development of pre‐emptive quarantine, monitoring and potential management options. Given the global nature of invasions by these insects, an international and collaborative research approach is required, where knowledge and tools for study can be shared in a more effective manner. [ABSTRACT FROM AUTHOR]

Human-associated introduction of pathogens and consequent invasions is very evident in areas where no related organisms existed before. In areas where related but distinct populations or closely related cryptic species already exist, the invasion process is much harder to unravel. In this study, the population structure of the Eucalyptus leaf pathogen Teratosphaeria nubilosa was studied within its native range in Australia, including both commercial plantations and native forests. A collection of 521 isolates from across its distribution was characterized using eight microsatellite loci, resulting in 112 multilocus haplotypes (MLHs). Multivariate and Bayesian analyses of the population conducted in structure revealed three genetically isolated groups (A, B and C), with no evidence for recombination or hybridization among groups, even when they co-occur in the same plantation. DNA sequence data of the ITS ( n = 32), β-tubulin ( n = 32) and 27 anonymous loci ( n = 16) were consistent with microsatellite data in suggesting that T. nubilosa should be considered as a species complex. Patterns of genetic diversity provided evidence of biological invasions by the pathogen within Australia in the states of Western Australia and New South Wales and helped unravel the pattern of invasion beyond Australia into New Zealand, Brazil and Uruguay. No significant genetic differences in pathogen populations collected in native forests and commercial plantations were observed. This emphasizes the importance of sanitation in the acquisition of nursery stock for the establishment of commercial plantations. [ABSTRACT FROM AUTHOR]

Aims To highlight the increasing importance of pests and pathogens to Australian Acacia species, where they are planted as non-natives in commercial plantations and in their native environment. Location Africa, Asia, Australia, South America. Methods Existing literature and results of unpublished surveys on pests and pathogens of Australian acacias are reviewed. These are discussed within the context of a growing importance of invasive alien insects and pathogens including novel encounters and host jumps. Results Australian acacias planted as non-natives in various parts of the world are increasingly threatened by pests and pathogens. These include those that are accidentally being introduced into the new environments as well as 'new encounter' pests and pathogens that are undergoing host shifts to infect non-native acacias. Furthermore, insects and pathogens for biological control of invasive Australian acacias present substantial challenges for plantation forestry. Main conclusions Pests and pathogens will seriously challenge plantation forestry based on non-native Australian acacias. In the longer term, new encounter pests and pathogens will also threaten these trees in their native environments. [ABSTRACT FROM AUTHOR]

Chrysoporthe cubensisis an important pathogen of commercially planted Eucalyptusspecies (Myrtaceae) in tropical and subtropical parts of the world where these trees are planted as non-natives. Although the majority of Eucalyptusspp. are native to Australia, Chr. cubensisis not common there and has been reported only once from naturally growing Eucalyptus marginatain Western Australia. Chr. cubensisis able to infect hosts in the Myrtaceae and Melastomataceae other than Eucalyptus, but has not been found on hosts other than Eucalyptusin Australia. Recently, fruiting structures resembling those of Chr. cubensiswere discovered on Tibouchina heteromalla, planted as a non-native in the Botanical Gardens in Cairns, northern Queensland. These fruiting structures and resulting isolates were characterised as Chr. cubensisin this study. Pathogenicity studies found that Corymbiaspp., including commercially important spotted gum, are susceptible along with E. pilularisand E. dunnii. The discovery of Chr. cubensison a non-native plant in the northern part of Australia is important as it might imply that the pathogen has been introduced into the country and pose a significant threat to native Eucalyptusforests. Alternatively, this fungus might occur naturally in the area on hosts other than Tibouchina, possibly Eucalyptusor related species, and that Australia forms part of its native range. [ABSTRACT FROM AUTHOR]

The majority of Mycosphaerella species from eucalypts (Eucalyptus, Corymbia and Angophora) in Australia have been recorded only from trees growing in plantations. This illustrates a bias in research in the past two decades toward commercial enterprise, and it emphasises a lack of understanding of the occurrence of these important fungi under natural conditions. Smweys of foliar fungi in native forests in eastern Australia, as well as adjacent plantations, thus have been initiated in recent years. In this study we describe four new species of Mycosphaerella from Eucalyptus spp. as well as other Myrtaceae. Mycosphaerella tumulosa sp. nov. (anamorph: Pseudocercospora sp.) was found on more than seven species of Eucalyptus and Corymbia in native forests and plantations in northeastern New South Wales and southeastern Queensland and appears to be relatively common, although not damaging to these trees. Mycosphaerella multiseptata sp. nov. was recorded from several locations on species of Angophora in native forests and amenity plantings. Mycosphaerella pseudovespa sp. nov. was found in one location in native forest on E. biturbinata. The first species of Mycosphaerella to be described from Syncarpia, M. syncarpiae sp. nov., was found in native forests in numerous locations from Sydney through to northeastern New South Wales and appears to be relatively common. [ABSTRACT FROM AUTHOR]

The majority of Eucalyptus species are native to Australia, but worldwide there are over 3 million ha of exotic plantations, especially in the tropics and subtropics. Of the numerous known leaf diseases, three species of Phaeophleospora can cause severe defoliation of young Eucalyptus; Phaeophleospora destructans, Phaeophleospora eucalypti and Phaeophleospora epicoccoides. Phaeophleospora destructans has a major impact on seedling survival in Asia and has not, as yet, been found in Australia where it is considered a serious threat to the biosecurity of native eucalypts. It can be difficult to distinguish Phaeophleospora species based on symptoms and micromorphology and an unequivocal diagnostic tool for quarantine purposes would be useful. In this study, a multiple gene genealogy of these Phaeophleospora species and designed specific primers has been constructed to detect their presence from leaf samples. The phylogenetic position of these Phaeophleospora species within Mycosphaerella was established. They are closely related to each other and to other important Eucalyptus pathogens, Mycosphaerella nubilosa, Mycosphaerella cryptica and Colletogloeopsis zuluensis. The specific primers developed can now be used for diagnostic and screening purposes within Australia. [ABSTRACT FROM AUTHOR]

Gonipterus species are pests of Eucalyptus plantations worldwide. The egg parasitoid wasp Anaphes nitens is used in many countries for the biological control of Gonipterus spp. Recent taxonomic studies have shown that the three invasive Gonipterus spp., which were previously considered as G. scutellatus, form part of a cryptic species complex. These taxonomic changes have implications for the biological control of Gonipterus spp. The aims of this study were to understand the species composition and distribution of Gonipterus spp. and their egg parasitoids in Australia. Gonipterus spp. adults and egg capsules were collected in south-eastern Australia and Tasmania. Adult Gonipterus were identified using morphology and DNA barcoding. Parasitoids were reared from Gonipterus egg capsules and identified. Thirteen Gonipterus species were collected: twelve species were found on the Australian mainland and one species in Tasmania. These included three described species, four previously recognized but undescribed species, two undescribed species and four unidentified species. Five egg parasitoid species that attack Gonipterus spp. were identified. Anaphes nitens, Centrodora damoni and Euderus sp. were identified on the Australian mainland and A. tasmaniae and A. inexpectatus were identified in Tasmania. The results from this study will contribute to the improvement of Gonipterus biological control in the future. [ABSTRACT FROM AUTHOR]

Abstract: Surveys of Australian and South African rivers revealed numerous Phytophthora isolates residing in clade 6 of the genus, with internal transcribed spacer (ITS) gene regions that were either highly polymorphic or unsequenceable. These isolates were suspected to be hybrids. Three nuclear loci, the ITS region, two single copy loci (antisilencing factor (ASF) and G protein alpha subunit (GPA)), and one mitochondrial locus (cytochrome oxidase c subunit I (coxI)) were amplified and sequenced to test this hypothesis. Abundant recombination within the ITS region was observed. This, combined with phylogenetic comparisons of the other three loci, confirmed the presence of four different hybrid types involving the three described parent species Phytophthora amnicola, Phytophthora thermophila, and Phytophthora taxon PgChlamydo. In all cases, only a single coxI allele was detected, suggesting that hybrids arose from sexual recombination. All the hybrid isolates were sterile in culture and all their physiological traits tended to resemble those of the maternal parents. Nothing is known regarding their host range or pathogenicity. Nonetheless, as several isolates from Western Australia were obtained from the rhizosphere soil of dying plants, they should be regarded as potential threats to plant health. The frequent occurrence of the hybrids and their parent species in Australia strongly suggests an Australian origin and a subsequent introduction into South Africa. [Copyright &y& Elsevier]

After recent changes to the taxonomy of the Botryosphaeriaceae species with diplodia-like (= dark, ovoid, often pigmented) conidia are considered to belong to at least three genera including Diplodia, Lasiodiplodia and Dothiorella. In a recent molecular phylogenetic study it became apparent that two groups of isolates with diplodia-like conidia required taxonomic revision. One group of isolates originated from Cupressus sempervirens in Greece and Cyprus and had been identified as D. pinea f. sp. cupressi based on morphological characteristics. The other isolates originated from a Casuarina sp. in Australia and were superficially similar to those in the first group based on their morphologically similar diplodia-like conidia. The aim of this study was to resolve the taxonomy of these two groups of isolates by combining the information from the multiple gene genealogies with morphological characters. The results showed that the isolates from C. sempervirens in Greece and Cyprus represent D. cupressi. The isolates from Casuarina in Australia belong to the more distantly related genus Dothiorella and represent a distinct species that is described here as Do. casuarini sp. nov.

Ophiostoma ips is a common fungal associate of various conifer-infesting bark beetles in their native ranges and has been introduced into non-native pine plantations in the Southern Hemisphere. In this study, we used 10 microsatellite markers to investigate the population biology of O. ips in native (Cuba, France, Morocco and USA) and non-native (Australia, Chile and South Africa) areas to characterize host specificity, reproductive behaviour, and the potential origin as well as patterns of spread of the fungus and its insect vectors. The markers resolved a total of 41 alleles and 75 haplotypes. Higher genetic diversity was found in the native populations than in the introduced populations. Based on the origin of the insect vectors, the populations of O. ips in Australia would be expected to reflect a North American origin, and those in Chile and South Africa to reflect a European origin. However, most alleles observed in the native European population were also found in the native North American population; only the allele frequencies among the populations varied. This admixture made it impossible to confirm the origin of the introduced Southern Hemisphere (SH) populations of O. ips. There was also no evidence for specificity of the fungus to particular bark beetle vectors or hosts. Although O. ips is thought to be mainly self-fertilizing, evidence for recombination was found in the four native populations surveyed. The higher genetic diversity in the North American than in the European population suggests that North America could be the possible source region of O. ips.

Species within the genus Botryosphaeria include some of the most widespread and important pathogens of woody plants, and have been the focus of numerous taxonomic studies in recent years. It is currently accepted that anamorphs of Botryosphaeria belong to two distinct genera, Fusicoccum and Diplodia. Species within the genus Fusicoccum commonly produce aseptate, hyaline conidia. In the present study, fungi were isolated from foliage and wood of Eucalyptus in native forests and plantations in Australia. Although these fungi produced Dichomera anamorphs in culture, they clustered within the Fusicoccum clade of Botryosphaeria based on their ITS sequence data. Four species, Botryosphaeria dothidea, B. parva, B. ribis and B. australis produced Dichomera conidia in culture. The Dichomera synanamorphs are described for these four species of Botryosphaeria. In addition, falling within the Fusicoccum clade of Botryosphaeria, two species were found to be distinct from previously described Botryosphaeria spp. based on their ITS sequences, but synonymous with D. versiformis and D. eucalypti. These observations are currently unique to isolates from host trees within the genus Eucalyptus in Australia, and the pleoanamorphic nature of these species is discussed.

The Ophiostoma piceae species complex incorporates several economically important species, including serious tree pathogens and agents of bluestain. The species in the complex are morphologically similar, but can be distinguished from each other based on morphology, biology, mating type studies and molecular data. At present, all the species in the complex are considered to be native to the Northern Hemisphere, most of them with a very wide distribution. Only a few sporadic reports of members of the complex are available from the Southern Hemisphere, where they are believed to have been introduced, including New Zealand, Australia, Chile, Brazil and Uruguay. This study aims to confirm the identity of isolates resembling O. piceae originating from three Southern Hemisphere countries, using mating compatibility and rDNA sequencing. Our results show that O. quercus is widely distributed throughout South Africa on both native and exotic hardwoods. O. quercus is also reported for the first time from Brazil, again from a native host. O. floccosum is reported for the first time from South Africa, but from an exotic Pinus sp. These results suggest that species of the O. piceae complex are common in the Southern Hemisphere, and that current views on the origins of especially O. quercus need to be reconsidered.