Historical range contraction,and not taxonomy,explains the contemporary genetic structure of the Australian tree <Emphasis Type="Italic">Acacia dealbata</Emphasis> Link

Irrespective of its causes, strong population genetic structure indicates a lack of gene flow. Understanding the processes that underlie such structure, and the spatial patterns it causes, is valuable for conservation efforts such as restoration. On the other hand, when a species is invasive outside its native range, such information can aid management in the non-native range. Here we explored the genetic characteristics of the Australian tree Acacia dealbata in its native range. Two subspecies of A. dealbata have previously been described based on morphology and environmental requirements, but recent phylogeographic data raised questions regarding the validity of this taxonomic subdivision. The species has been widely planted within and outside its native Australian range and is also a highly successful invasive species in many parts of the world. We employed microsatellite markers to investigate the population genetic diversity and structure among 42 A. dealbata populations from across the species’ native range. We also tested whether environmental variables purportedly relevant for the putative separation of subspecies are linked with population genetic differentiation. We found no relationship between population genetic structure of A. dealbata in Australia and these environmental features. Rather, we identified two geographically distinct genetic clusters that corresponded with populations in the northeastern part of mainland Australia, and the southern mainland and Tasmanian range of the species. Our results do not support the taxonomic subdivision of the species into two distinct subspecies based on environmental features. We therefore assume that the observed morphological differences between the putative subspecies are plastic phenotypic responses. This study provides population genetic information that will be useful for the conservation of the species within Australia as well as to better understand the invasion dynamics of A. dealbata.     

Diminishing importance of elaiosomes for acacia seed removal in non-native ranges

Myrmecochorous plants produce seeds with lipid-rich appendages (elaiosomes) which act as a reward for seed-dispersing ants. Seed dispersal is important for exotic species, which often need to establish new mutualistic interactions in order to colonize new non-native habitats. However, little is known about the importance of elaiosomes for seed removal in many of their non-native ranges. We studied ant–seed interactions of elaiosome-bearing and elaiosome-removed seeds of the Australian trees Acacia dealbata and Acacia longifolia in order to assess the relative importance of elaiosomes for seed removal between their native (Australia) and non-native (Portugal) ranges. In Portugal, we also studied the co-occurring native plant species with myrmecochorous seeds, Pterospartum tridentatum and Ulex europaeus, across three contiguous levels of acacia invasion: control (i.e. no acacia), low, and high acacia tree density. Acacia seeds were successfully removed by ants in their non-native region by a diversified assemblage of ant species, even in sites where native plants interacted with only one specialized ant species. In the invaded range, diminishing relative importance of elaiosomes was associated with changes in the ant community due to acacia invasion, and for A. dealbata, ant species richness decreased with increasing acacia tree density. Although seed removal was high for both acacia species, the importance of elaiosomes was proportionally lower for A. dealbata in the non-native region. Native plant species experienced significant reductions in seed removal in areas highly invaded by acacia, identifying another mechanism of displacement of native plants by acacias.     

Feasibility assessment for the classical biological control of <Emphasis Type="Italic">Tamarix</Emphasis> in Argentina

Saltcedars are woody plants in the genus Tamarix L. (Caryophyllales: Tamaricaceae) and are native to Eurasia and Africa. Several species have become invasive in the Americas, Australia and South Africa. In Argentina there are four species of Tamarix distributed in arid, semi-arid and coastal areas of most provinces. The taxonomic isolation of Tamarix spp. in Argentina, their widespread distribution, negative impact to natural areas and lack of impact from existing natural enemies all indicate that Tamarix is an ideal candidate for classical biological control in Argentina. Biological control of Tamarix spp. has been rapid and highly successful in the USA after the introduction of four Diorhabda spp. (Coleoptera: Chrysomelidae). Biological control of Tamarix spp. in Argentina could be implemented easily, rapidly, and at a low cost by utilizing the information developed in the USA.     

The potential range of <Emphasis Type="Italic">Ailanthus altissima</Emphasis> (tree of heaven) in South Africa: the roles of climate,land use and disturbance

Invasive trees are a major problem in South Africa. Many species are well established whereas others are still in the early stages of invasion. The management of invasive species is most cost effective at the early stages of invasion; it is thus essential to target and contain naturalizing invaders before they spread across the landscape. Multi-scale species distribution models (SDMs) provide useful insights to managers; they combine species-occurrence observations with climatic variables to predict potential distributions of alien species. Applying SDMs in human-dominated ecosystems is complicated because many factors associated with human actions interact in complex ways with climatic and edaphic factors to determine the potential suitability of sites for species. The aim of this study was to determine the degree to which a worldwide invader, A. altissima (Simaroubaceae) has occupied its potential range in South Africa, to identify areas at risk of future invasion. To do this we built a set of SDMs at both global and country scales using climatic, land use and human-footprint data. Climatic data best explained the distribution of A. altissima at the global scale whereas variables reflecting human-mediated disturbances were most influential at the national scale. Our analyses show the importance of human-mediated disturbances at a global scale and human occupancy at a country scale in determining the range limits of A. altissima. Populations of this tree species are already present in most parts of South Africa that are environmentally suitable for the species, and management actions need to focus on preventing increases in density in these areas.     

Plastomes of Mimosoideae: structural and size variation,sequence divergence,and phylogenetic implication

Plastomes of Fabaceae show both significant structural and size variation; however, most published plastomes are from subfamily Papilionoideae and only a few are from the other two subfamilies. In order to address the plastome structural and size variation of subfamily Mimosoideae, we integrated 11 newly sequenced plastomes from representing genera with three previously published ones. Each mimosoid plastome presented a typical quadripartite structure and contained 111 unique genes. Their inverted repeats (IRs) experienced multiple expansion/contraction; a ca. 13-kb IR expansion into small single copy (SSC) was detected in plastomes of a clade formed by tribe Ingeae and Acacia sensu stricto (s.s.), and a ca. 1.7-kb IR expansion into and a ca. 1.9-kb contraction out of large single copy (LSC) were found in Pithecellobium flexicaule and Acacia dealbata, respectively. Linear regression analysis showed decreased synonymous substitution rates of genes relocating from SSC into IR. A loss of both introns of clpP occurred in A. dealbata and Faidherbia albida, and a duplicated clpP copy was detected in A. dealbata. Furthermore, a 421-bp inversion that containing rps18 was found in A. dealbata. The size of mimosoid plastomes was found significantly affected by a IR-SC boundary shift, and also associated with repeat content. Plastome coding and noncoding regions with variable sequence divergence may supply valuable markers for molecular evolutionary and phylogenetic studies at different taxonomic levels. Plastid phylogenomics well resolved relationships among sampled mimosoid species.     

<Emphasis Type="Italic">Tamarix</Emphasis> (Tamaricaceae) hybrids: the dominant invasive genotype in southern Africa

Hybridization is regarded as a rapid mechanism for increasing genetic variation that can potentially enhance invasiveness. Tamarix hybrids appear to be the dominant genotypes in their invasions. Exotic Tamarix are declared invasive in South Africa and the exotic T. chinensis and T. ramosissima are known to hybridize between themselves, and with the indigenous T. usneoides. However, until now, it was not known which species or hybrid is the most prevalent in the invasion. With a biocontrol programme being considered as a way of suppressing the alien Tamarix populations, it is important to document the population genetic dynamics of all species in the region. This investigation sought to identify Tamarix species in southern Africa and their hybrids, describe their population structure, and reveal the geographic origin of the invasive species. To achieve this, nuclear Internal Transcribed Spacer (ITS) sequence data and the multilocus Amplified Fragment Length Polymorphisms (AFLPs) markers were used. Phylogenetic analysis and population genetic structure confirmed the presence of three species in South Africa (T. chinensis, T. ramosissima and T. usneoides) with their hybrids. The indigenous T. usneoides is clearly genetically distant from the alien species T. chinensis and T. ramosissima. Interestingly, the Tamarix infestation in South Africa is dominated (64.7 %) by hybrids between T. chinensis and T. ramosissima. The exotic species match their counterparts from their places of origin in Eurasia, as well as those forming part of the invasion in the US.     

Invasive <Emphasis Type="Italic">Tamarix</Emphasis> (Tamaricaceae) in South Africa: current research and the potential for biological control

Most species of Tamarix originate in Eurasia and at least five species have become invasive around the world, including South Africa. However, T. usneoides is indigenous to southern Africa, where the potential for biological control of the invasive species is being investigated. Recent research on the invasive species is reviewed here with particular reference to these South African biocontrol efforts. The successful biological control programme against invasive Tamarix in the USA, using several species of “Tamarisk beetle”, is being used as a guide for the South African research. The South African programme is complicated by firstly, the presence of the indigenous T. usneoides which raises the precision of host-specificity required, and secondly, the introduced and indigenous Tamarix have a high intrinsic value for phytoremediation of mine tailings dams in South Africa. The phylogenetic proximity of these Tamarix species to each other has contributed to this challenge, which has nevertheless been successfully addressed by molecular techniques used to separate the species. In addition, classical morphological techniques have been used to separate the Tamarisk beetles, so that now they can generally be matched to Tamarix tree species. Overall, it is concluded that given the broad knowledge now available on the ecology and identity of both the trees and their biocontrol agents, the prospects for successful biological control of Tamarix in South Africa are good.     

Genetic diversity and structure of the globally invasive tree, <Emphasis Type="Italic">Paraserianthes lophantha</Emphasis> subspecies <Emphasis Type="Italic">lophantha</Emphasis>, suggest an introduction history characterised by varying propagule pressure

An emerging insight in invasion biology is that intra-specific genetic variation, human usage, and introduction histories interact to shape genetic diversity and its distribution in populations of invasive species. We explore these aspects for the tree species Paraserianthes lophantha subsp. lophantha, a close relative of Australian wattles (genus Acacia). This species is native to Western Australia and is invasive in a number of regions globally. Using microsatellite genotype and DNA sequencing data, we show that native Western Australian populations of P. lophantha subsp. lophantha are geographically structured and are more diverse than introduced populations in Australia (New South Wales, South Australia, and Victoria), the Hawaiian Islands, Portugal, and South Africa. Introduced populations varied greatly in the amount of genetic diversity contained within them, from being low (e.g. Portugal) to high (e.g. Maui, Hawaiian Islands). Irrespective of provenance (native or introduced), all populations appeared to be highly inbred (F _IS ranging from 0.55 to 0.8), probably due to selfing. Although introduced populations generally had lower genetic diversity than native populations, Bayesian clustering of microsatellites and phylogenetic diversity indicated that introduced populations comprise a diverse array of genotypes, most of which were also identified in Western Australia. The dissimilarity in the distribution and number of genotypes in introduced regions suggests that non-native populations originated from different native sources and that introduction events differed in propagule pressure.     

Chemical and molecular identification of the invasive termite <Emphasis Type="Italic">Zootermopsis nevadensis</Emphasis> (Isoptera: Archotermopsidae) in Japan

Numerous termite species have been introduced outside their native ranges by human transport, and some have become invasive. The dampwood termite Zootermopsis nevadensis (Hagen), which is native to western North America, has been introduced to and become established in Kawanishi City, Hyogo Prefecture, Japan. Zootermopsis nevadensis is subdivided into two subspecies based on cuticular hydrocarbon (CHC) phenotypes: Z. nevadensis nevadensis and Z. nevadensis nuttingi (Haverty and Thorne). Here, we identified Z. nevadensis in Japan as hybrids between the two subspecies. Chemical analysis showed the presence of 7,15-dimethylhenicosane and 5,17-dimethylhenicosane in the CHCs of Z. nevadensis in Japan, corresponding to the CHC phenotype of Z. n. nevadensis. Conversely, all mitochondrial cytochrome c oxidase subunit I sequences of Z. nevadensis in Japan were identical to sequences from Z. n. nuttingi and hybrids between the two subspecies from a native hybrid zone in California, USA. In addition, phylogenetic analysis showed that Z. nevadensis in Japan formed a clade with Z. n. nuttingi and hybrids between the two subspecies. Our results show discordance between the chemical and genetic features of Z. nevadensis in Japan, indicating that individuals of Z. nevadensis in Japan are hybrids between the two subspecies.     

Evaluating the efficacy of <Emphasis Type="Italic">Hypogeococcus</Emphasis> sp. as a biological control agent of the cactaceous weed <Emphasis Type="Italic">Cereus jamacaru</Emphasis> in South Africa

We evaluated the efficacy of Hypogeococcus sp. (Hemiptera: Pseudococcidae) as a biological control agent of the cactaceous weed Cereus jamacaru De Candolle (Queen of the Night cactus) in South Africa. This weed has been described as being under complete biological control due to the action of Hypogeococcus sp., although no formal post-release evaluation had been conducted prior to this study. Biological control was associated with significant reductions in fruiting, plant survival and plant densities, while plant population age structures were negatively affected. Weed populations infected by Hypogeococcus sp. were typified by low or non-existent recruitment and are expected to diminish with time. Populations where Hypogeococcus sp. was absent displayed extensive recruitment, and are predicted to expand or self-replace, if left unchecked. These data indicate that Hypogeococcus sp. has a significant negative effect on C. jamacaru at the individual plant and population level, and given sufficient time provides complete biological control over this weed in South Africa.     

Molecular Phylogeny of Serotines (Mammalia,Chiroptera, <Emphasis Type="Italic">Eptesicus</Emphasis>): Evolutionary and Taxonomical Aspects of the <Emphasis Type="Italic">E. serotinus</Emphasis> Species Group

This article provides a phylogenetic analysis of five nuclear and mitochondrial cytochrome b genes of palaearctic serotines. Nuclear data yield five monophyletic clades: Botta’s serotine and the South African long-tailed house bat E. hottentottus; the common serotine bat (including all studied E. serotinus subspecies and andersoni form of undefined status) and the meridional serotine E. isabellinus; the Gobi serotine, including Bobrinski’s serotine; the northern bat; and New World serotines. We found latest taxonomic decisions regarding mirza and pachyomus questionable and needing further revision. The significant inconsistency between mitochondrial and nuclear phylogenies obtained for genes of different inheritance systems suggests repetitive introgression events in the evolution of the genus.     

Present and future distribution of three aquatic plants taxa across the world: decrease in native and increase in invasive ranges

Inland aquatic ecosystems are vulnerable to both climate change and biological invasion at broad spatial scales. The aim of this study was to establish the current and future potential distribution of three invasive plant taxa, Egeria densa, Myriophyllum aquaticum and Ludwigia spp., in their native and exotic ranges. We used species distribution models (SDMs), with nine different algorithms and three global circulation models, and we restricted the suitability maps to cells containing aquatic ecosystems. The current bioclimatic range of the taxa was predicted to represent 6.6–12.3% of their suitable habitats at global scale, with a lot of variations between continents. In Europe and North America, their invasive ranges are predicted to increase up to two fold by 2070 with the highest gas emission scenario. Suitable new areas will mainly be located to the north of their current range. In other continents where they are exotic and in their native range (South America), the surface areas of suitable locations are predicted to decrease with climate change, especially for Ludwigia spp. in South America (down to ?55% by 2070 with RCP 8.5 scenario). This study allows to identify areas vulnerable to ongoing invasions by aquatic plant species and thus could help the prioritisation of monitoring and management, as well as contribute to the public awareness regarding biological invasions.     

New records of an invasive bumble bee in northern Chile: expansion of its range or new introduction events?

The Eurasian bumble bee Bombus terrestris Linnaeus has been used commercially for pollination of a large number of crop species worldwide. This species has become invasive in several countries where it has escaped into natural environments. This species has become naturalized in many zones of Chile and southern Argentina, and may potentially invade other regions and countries in South America. These naturalized populations of B. terrestris have been associated with rapid population declines of the native bee B. dahlbomii Guérin-Méneville. We report new records of the exotic bee B. terrestris in the Region de Arica y Parinacota in the far north of Chile, which includes portions of the Atacama Desert. We used species distribution models (SDMs) and multivariate analyses to evaluate whether these occurrences represent new escapes from managed colonies or natural dispersal of the species from its southern invaded range. These reports of B. terrestris indicate a northward expansion of this bee. In our analyses, these new areas of occurrences have environmental conditions similar to those observed in the species’ southern invaded range, and our SDMs predict that B. terrestris dispersal through the Atacama is possible, although not likely given the occasional flower blooming in that region of Chile. These new occurrences in northern Chile reflect a potential for future invasion into other regions of South America by B. terrestris. Future surveys in the area should be intensified to evaluate if viable populations of this invasive species may become established.     

Identification and genetic diversity of two invasive <Emphasis Type="Italic">Pissodes</Emphasis> spp. Germar (Coleoptera: Curculionidae) in their introduced range in the southern hemisphere

During the first half of the twentieth century, two accidental cases of introduction of Pissodes weevils were recorded from the southern hemisphere. The weevils in South Africa were identified as the deodar weevil (Pissodes nemorensis) and those in South America as the small banded pine weevil (Pissodes castaneus). Wide distribution of the two species in their invasive range, general difficulty in identifying some Pissodes spp., and the varying feeding and breeding behaviours of the species in South Africa has necessitated better evidence of species identity and genetic diversity of both species and population structure of the species in South Africa. Barcoding and the Jerry-to-Pat region of the COI gene were investigated. Morphometric data of the South African species was analysed. Our results confirmed the introduction of only one Pissodes species of North American origin to South Africa. However, this species is not P. nemorensis, but an unrecognized species of the P. strobi complex or a hybrid between P. strobi and P. nemorensis. Only P. castaneus, of European origin, was identified from South America. We identified ten mitochondrial DNA haplotypes from South Africa with evidence of moderate genetic structure among geographic populations. Terminal leader and bole-feeding weevils did not differ at the COI locus. A single haplotype was identified from populations of P. castaneus in South America. Results of the present study will have implications on quarantine, research and management of these insect species.     

Taxonomic and functional diversity in <Emphasis Type="Italic">Calogaya</Emphasis> (lichenised Ascomycota) in dry continental Asia

The genus Calogaya (Teloschistaceae, Xanthorioideae) was established to accommodate mainly epilithic lichens with lobate thalli, previously regarded as the “Caloplaca saxicola group.” Data supporting the recognition of this new genus came from European lichens, and although the genus is soundly based, we have found in Asia numerous epiphytic lineages and lineages with reduced, non-lobate thallus in dry continental areas. The taxonomic and functional diversity of Calogaya is distinctly higher in steppe and desert areas of Asia than in the less arid regions of Europe. We sampled 238 specimens, mostly from arid regions of north-western China, Iran, southern Siberia and Turkey. Three nuclear DNA loci were analysed separately and jointly by Bayesian inference, maximum likelihood and *BEAST approaches. Delimitations of 28 putative species were tested by BP&P multispecies coalescent model with joint analysis of species delimitation and species-tree estimation. Finally, we recognised 22 taxonomic units: 16 are at species rank, 3 are treated as subspecies and 3 are complexes, treated here as a single entity, but in reality probably including more than one species. Calogaya altynis, C. biatorina subsp. asiatica, C. decipiens subsp. esorediata, C. haloxylonis, C. orientalis, C. xanthoriella and C. xinjiangis are newly described. Caloplaca zoroasteriorum is combined into Calogaya, and Calogaya persica is reduced to a subspecies. The taxonomic status of Calogaya saxicola is unclear, and the name is employed here “sensu lato” for several non-monophyletic epilithic lineages with short-lobed thalli. Calogaya biatorina and C. ferrugineoides are the two other heterogeneous taxonomic units probably including more species.     

<Emphasis Type="Italic">Anoplodiscus</Emphasis> Sonsino, 1890 (Monogenea: Anoplodiscidae): a new Australian species,and the first African record from South African hosts

Species of Anoplodiscus Sonsino, 1890 were previously only known from host members of Sparidae. A new species, Anoplodiscus hutsonae n. sp. is proposed for museum specimens originally collected from species of Scolopsis Cuvier (Nemipteridae) off Heron Island and Lizard Island, Australia. Additionally, Anoplodiscus tai Ogawa, 1994 is synonymised with Anoplodiscus cirrusspiralis Roubal, Armitage & Rohde, 1983 due to a lack of support for differential characters, and Anoplodiscus richiardii is considered a species inquirenda. Anoplodiscus cirrusspiralis causes visible lesions on the skin and fins of its host, and may also contribute to poor food conversion rates in sparid aquaculture. Anoplodiscus cirrusspiralis has been recorded from cultured sparids in Australia, Japan, South Africa, and South Korea, and was implicated as a disease agent in fish from the former two countries. However, the discovery of A. cirrusspiralis on Chrysoblephus gibbiceps (Valenciennes), Ch. laticeps (Valenciennes) and Cymatoceps nasutus (Castelnau) in South Africa, ?Pagrus major (Temminck & Schlegel) in South Korea, and P. auratus (Forster) in Australia, New Zealand and Japan suggests that this species may have a wide distribution and low host-specificity within the Sparidae. In South Africa, A. cirrusspiralis was first encountered on a morbid C. nasutus and Ch. gibbiceps from two public aquaria in 2009 (Two Oceans Aquarium, Cape Town and uShaka Sea World, Durban, respectively). Additional material was collected from C. laticeps kept at an abalone farm in Hermanus that originated from Struisbaai on the South African south coast. Anoplodiscus cirrusspiralis is redescribed from the South African specimens. This is the first record of a member of Anoplodiscidae Tagliani, 1912 from Africa.     

Molecular phylogeny of the genus <Emphasis Type="Italic">Bolusiella</Emphasis> (Orchidaceae,Angraecinae)

Recent molecular studies have suggested the monophyly of Bolusiella, a small orchid genus comprising five species and one subspecies from Continental Africa, but sampling has been limited. Using the species delimitation presented in the recent taxonomic revision of the genus, this study aimed to confirm the monophyly of Bolusiella and assess the interspecific relationships using a comprehensive sampling and various analytical methods. DNA sequences of one nuclear spacer region (ITS-1) and five plastid regions (matK, rps16, trnL–trnF, trnC–petN, and ycf1) from 20 specimens representing all five species of the genus were analyzed using static homology, dynamic homology, and Bayesian methods. The monophyly of both the genus Bolusiella and each of its five species was confirmed, corroborating the previously published taxonomic revision. The use of dynamic homology methods was not conclusive for this particular group. The results of the total evidence analysis (combining all six sequence regions) using the dynamic homology approach yielded a slightly different hypothesis regarding interspecific relationships (namely the exchange of B. talbotii and Bolusiella iridifolia as the earliest diverging lineage), probably because the nodes in question are supported by a small subset of conflicting characters, compared to the hypotheses resulting from the static homology and Bayesian methods, which are congruent with the results of previous studies.     

Revision of the carabid genus <Emphasis Type="Italic">Meroctenus</Emphasis> Gemminger et Harold,with a new status of <Emphasis Type="Italic">Xenodochus</Emphasis> Andrewes (Coleoptera,Carabidae: Harpalini)

Originally described as a monotypical genus with unclear taxonomic position from Sudan, Meroctenus Gemminger et Harold, 1868 is treated as a polytypical genus of the Selenophori genus group with two subgenera: Meroctenus s. str. and Xenodochus Andrewes, 1941, stat. n. (the latter was previously considered a distinct genus). Within Meroctenus, two species are recognized: M. (Meroctenus) crenulatus Chaudoir, 1843 (type species) and M. (M.) mediocris (Andrewes, 1936), comb, n., transferred to Meroctenus s. str. from Xenodochus. A new subspecies M. (M.) crenulatus orientalis subsp. n. is described from Pakistan. Diagnoses of the genus Meroctenus in new interpretation as well as of its two subgenera are discussed, and a taxonomic review of the subgenus Meroctenus s. str. with a key to the species and subspecies is provided. The following synonymy is proposed: Meroctenus Gemminger et Harold, 1868 = Paregaploa Müller, 1947, syn. n.; Meroctenus crenulatus (Chaudoir, 1843) = Egaploa (Paregaploa) conviva Müller, 1947, syn. n. Lectotypes are designated for Ctenomerus crenulatus Chaudoir, 1843 and Xenodus mediocris Andrewes, 1936.