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There is ample anecdotal evidence and expert opinion on the adverse impact of imported biological control agents on populations of invasive plants, but still a paucity of quantitative data. Asparagus asparagoides (bridal creeper), a perennial climber with an extensive below-ground network of rhizomes and tubers, was considered one of the most invasive plants of natural ecosystems in southern Australia in the 1990s. A long-term experiment was conducted at 15 sites invaded by A. asparagoides across Australia to determine whether its growth and reproduction declined following the release of two biological control agents: a leafhopper (undescribed Erythroneuri formerly referred to as Zygina sp.) and rust fungus (Puccinia myrsiphylli). Data on A. asparagoides were collected annually at each site for up to 3 years before the release of one or both agents in 2000 or 2001, and up to 7 years after release to capture spatial and temporal variability. Our results showed a steady decrease in A. asparagoides seedling and shoot density, and total above-ground biomass in quadrats across all sites in the years following the release of the leafhopper and/or rust fungus. The number of fruits produced in quadrats greatly varied between sites, although for most sites, fruit numbers before the release of agents were higher than after release. Changes in A. asparagoides climbing onto standardized trellises, however, were not consistent across sites during the same period, with major reductions in plant measurements recorded at some sites but not others. Differences in climatic conditions between sites during A. asparagoides growing season did not explain these variable results. Incidence of leafhopper damage on A. asparagoides cladodes in quadrats and trellises was generally lower than that of rust infection.

Asparagus asparagoides (L.) Druce (�� Elide asparagoides (L.) Kergu��len) ��� Secteur Incudine-Bavella, Propriano, bord de la route D319, �� l���E de l���h��tel Belambra, quelques pieds, terrain vague au S de la route menant �� la plage du Lido et p��riph��rie du lotissement de Paratella, tr��s nombreux pieds, 9.2.2017, Paradis, G. & C. Piazza pointage GPS et photos. Plante envahissante, nouvelle pour le secteur IncudineBavella. Ses autres localisations sur la c��te occidentale sont �� Ajaccio (PARADIS, Monde Pl. 475: 16-20, 2002), Tiuccia et L�����le Rousse (ALPHAND et al., Candollea 58: 276, 2003; PARADIS & PIAZZA, Monde Pl. 482: 1-2, 2004). Sur la c��te orientale, elle n���est connue que d���un seul point, pr��s de a Chiosura, au sud d���Alistro (DELAGE in PARADIS et al., 2009, poster, Coll. �� Specie esotiche invasive nel Sistema Sardo-Corse ��, 22 maggio 2009, Sassari). La plante change de statut de fr��quence et devient �� R �� (rare)., Published as part of Jeanmonod, Daniel & ��d., 2018, Notes �� la flore de Corse, XXVI, pp. 75-90 in Candollea 73 (1) on page 79, DOI: 10.15553/c2018v731a7, http://zenodo.org/record/5722166

Distribution in Corsica, in 2017, of the invasive species Asparagus asparagoides (L.) Druce. This article presents the results of our observations in 2017 on the distribution in Corsica of the invasive species Asparagus asparagoides (Asparagaceae). The plant is very abundant in L’Île Rousse and surroundings, Tiuccia, Ajaccio, Propriano and in a point of the eastern coast. Compared to the previous maps of 2002 and 2003, there is a significant expansion of the species, especially in Ajaccio., Cet article présente les résultats de nos observations en 2017 sur la répartition en Corse de l’espèce invasive Asparagus asparagoides (Asparagaceae). La plante est très abondante à L’Île Rousse et environs, Tiuccia, Ajaccio, Propriano et en un point de la côte orientale. Par rapport aux cartographies antérieures de 2002 et 2003, on constate une importante expansion de l’espèce, surtout à Ajaccio., Paradis Guilhan,Piazza Carole. Extension en Corse, en 2017, de l’espèce invasive Asparagus asparagoides (L.) Druce entre 2002 et 2017. In: Le Journal de botanique, n°80, 2017. Décembre. pp. 33-44.

The genus Asparagus is unusual in producing axillary, determinate organs called cladodes, which may take on either a flattened or cylindrical form. Here, we investigated the evolution of cladodes to elucidate the mechanisms at play in the diversification of shoot morphology. Our observations of Asparagus asparagoides , which has leaf-like cladodes, showed that its cladodes are anatomically and developmentally similar to leaves but differ in the adaxial/abaxial polarity of the vasculature. In addition to the expression of an ortholog of KNAT1 , orthologous genes that are normally expressed in leaves, ASYMMETRIC LEAVES1 and HD-ZIPIII , were found to be expressed in cladode primordia in a leaf-like manner. The cylindrical cladodes of Asparagus officinalis showed largely similar expression patterns but showed evidence of being genetically abaxialized. These results provide evidence that cladodes are modified axillary shoots, suggest that the co-option of preexisting gene networks involved in leaf development transferred the leaf-like form to axillary shoots, and imply that altered expression of leaf polarity genes led to the evolution of cylindrical cladodes in the A. officinalis clade.

Bridal creeper has become a serious environmental weed in southern Australia. Historically the invaded areas had low soil nutrient levels. However, our field surveys indicate that soils in bridal creeper–invaded areas have higher phosphorus and iron levels than soils in nearby native reference areas regardless of the proximity to agriculture or other disturbances. A glasshouse experiment was undertaken to determine the influence of increased nutrients on plants that co-occur with bridal creeper in order to (1) assess the impact of changed soil conditions and (2) predict the response of dominant species following the biological control of bridal creeper. The relative growth rate (RGR) of bridal creeper, two native shrubs (narrow-leaved thomasia [Thomasia angustifolia] and bluebell creeper [Billardiera heterophylla]), and an invasive exotic grass (annual veldt grass [Ehrharta longiflora]) were determined in three soil types: soil collected within a bridal creeper stand, soil collected from a nearby reference area, and a potting mix with nutrient levels higher than that recorded in the field. The plant species were chosen due to their association with bridal creeper. For example, the native species narrow-leaved thomasia was identified in a previous survey as the most abundant shrub at the invaded site where the soil was collected. The two other species, bluebell creeper and annual veldt grass, were identified from a previous seedbank trial as being abundant (in the seedbank) and able to readily germinate in invaded areas. When grown in either the bridal creeper–invaded soil or reference soil, bluebell creeper had significantly lower RGRs than narrow-leaved thomasia and annual veldt grass. However, as all these species showed increases in RGRs between reference soil and bridal creeper soil, this study indicates that for at least these three species the impact of increased nutrients may not be a barrier to the recovery of invaded areas following the control of bridal creeper.

Considerable progress has been made towards the successful classical biological control of many of Australia’s exotic weeds over the past decade. Some 43 new arthropod or pathogen agents were released in 19 projects. Effective biological control was achieved in several projects with the outstanding successes being the control of rubber vine, Cryptostegia grandiflora, and bridal creeper, Asparagus asparagoides. Significant developments also occurred in target prioritization, procedures for target and agent approval, funding, infrastructure and cooperation between agencies. Scientific developments included greater emphasis on climate matching, plant and agent phylogeny, molecular diagnostics, agent prioritization and agent evaluation.

To protect native biodiversity from environmental weeds, the impacts that these weeds cause need to be known before weed control commences. Asparagus asparagoides (L.) Druce (bridal creeper) (Asparagaceae) is a serious environmental weed and has been selected for biological control in Australia. To predict the responses of plant communities to the control of bridal creeper, a prerelease baseline of the impacts of bridal creeper on native plant communities was undertaken. Plant assemblages in areas invaded by bridal creeper were compared with reference areas that contained little or no bridal creeper. Areas invaded by bridal creeper contained 52% fewer native plant species when compared with nearby reference areas. However, there was no difference in the number of other exotic plant species between areas. Similar trends were found for the germinable seed bank. Although a greater number of exotic species were present in the seed bank compared with the vegetation surveys, there was still no difference between areas with and without bridal creeper. In a glasshouse trial, exotic species germinated more frequently compared with native species. This could indicate that as bridal creeper density decreases following control, exotic species have an advantage over native species when colonizing areas left vacant by bridal creeper. Second, as bridal creeper areas contained reduced native species richness and cover, they may be susceptible to further weed invasion after bridal creeper is removed. Therefore, simply reducing the presence of bridal creeper may not guarantee successful restoration of invaded areas and additional restoration efforts will be needed to ensure the ultimate goal of protecting native biodiversity is reached.

The difficulty of monitoring growth parameters of climbing invasive plants subjected to different control options can be overcome by using standardized support structures (trellises). The utility of such support structures on aboveground biomass accumulation and fruit production was demonstrated using the invasive climber, bridal creeper in three invaded nature reserves near Perth in Western Australia. Mean above-ground plant biomass for plots provided with trellises ranged from 204 ± 38 g/m2 to 336 ± 31 g/m2, whereas it ranged from 66 ± 10 g/m2 to 118 ± 10 g/m2 in plots with no trellises. The mean number of fruits/m2 produced on shoots in plots provided with trellises ranged from 424 ± 159 to 3,787 ± 873 and was up to almost four orders of magnitude greater than the number of fruits produced on plants in plots with no trellis (ranging from 0 to 5.25 ± 7.9). The use of standardized trellises also showed that fruit volume and fruit seed number can vary significantly between sites. Standardized trellises ha...

We reviewed in retrospect the selection process of agents for the biological control of bridal creeper (Asparagus asparagoides) in Australia. Selection of agents was facilitated by first investing resources, mostly in South Africa, to clarify identification of the target weed, locate most suitable areas to search for natural enemies, make preliminary observations on phenology, host range and impact of natural enemies and experimentally demonstrate indirect impact of a foliage feeder on below-ground biomass of bridal creeper. Although only limited climate modelling was performed to predict abundance of prioritised agents in Australia, their widespread distribution in South Africa was a good indication that they were likely to establish. No attempts were made to predict possible levels of parasitism that could be encountered in Australia and no formal assessment was undertaken to decide in what order prioritised agents should be released. Three of the four agents prioritised have now been released in Australia. The rust fungus Puccinia myrsiphylli (Thum.) G. Winter and leafhopper Zygina sp. have widely established and have already demonstrated their capacity to reduce significantly density of bridal creeper populations. It is still too early to determine the contribution that the third agent released, the Crioceris sp. leaf beetle, will make to the program.

A leaf beetle, Crioceris sp. (Coleoptera: Chrysomelidae), was introduced into Australia as a biological control agent of bridal creeper (Asparagus asparagoides L. Druce) during October 2002. Rearing of Crioceris sp. is labour intensive therefore all releases of Crioceris sp. have been under 1000 individuals, which may be too low to ensure establishment if high mortality and high competition with other agents occurs. The aim of this study is to understand how the presence of two well-established biocontrol agents, a rust fungus (Puccinia myrsiphylli (Thuem) Wint [Basidiomycota: Uredinales]) and a leafhopper (Zygina sp. [Hemiptera: Cicadellidae]), might influence Crioceris sp. establishment. Crioceris sp. neonate larvae were placed on bridal creeper plants with or without the leafhopper and/or rust. The number of larvae that pupated was reduced by 38 and 65% in the presence of the rust fungus and leafhopper, respectively and by 45% in the presence of both agents. As the area infected by the rust increased the area damaged by the leafhopper decreased. The rust appeared to be negatively impacted by the presence of the leafhopper. In a second experiment, female Crioceris sp. adults were given a choice between uninfested bridal creeper plants and those infested with the rust or the leafhopper. The females preferred to lay their eggs on plants without leafhoppers but did not seem to be deterred by the presence of the rust. Consequently, the performance and impact of Crioceris sp. on bridal creeper may be reduced if populations overlap with the other biocontrol agents in the field.

A new species of wasp, Stethynium sp. (Hymenoptera: Mymaridae), was found parasitizing eggs of an introduced weed biological control agent, Zygina sp. (Hemiptera: Cicadellidae), a leafhopper released against bridal creeper (Asparagus asparagoides L. Druce). A series of laboratory experiments was conducted to determine the development time and longevity of the wasp under different temperatures and the oviposition preference of the wasp for leafhopper eggs of different ages. Parasitized leafhopper eggs were placed in controlled temperature rooms set at either 15, 20, or 25°C and monitored for adult emergence. It was determined that development time of Stethynium sp. from egg to adult eclosion decreased as temperature increased and female wasps took longer to develop than males. Adult male and female wasps were placed in controlled temperature rooms set at these same temperatures and provided either water, a 10% sugar solution, or no food at all. Female wasps lived longer than males and sugar solution increased longevity significantly over no food or water alone, but this effect decreased with increasing temperature. Adult female wasps, given a choice between 1-, 2-, 3-, 5-, and 7-d-old eggs, showed no preference, and all progeny were able to develop and emerge at the same rate from any aged egg. Adult females also laid eggs in 8- and 9-d-old host eggs. There was a slight decrease in emergence rate from 9-d-old host eggs compared with 8-d-old eggs.

This paper examines the roles of plant demography, seed dispersal ecology and habitat suitability in influencing invasiveness of horticulturally important species. Section one investigates the relative invasiveness of two woody species, Crataegus monogyna and Prunus mahaleb, and concentrates on differences in demographic and dispersal traits. The second section delineates the invasion of two Asparagus spp. and concentrates on differences in seed dispersal ecology. Section three reports the use of a geographical information system analysis to determine whether habitat suitability, seed dispersal or land management is more important in determining threat of invasion by adventive Olea europaea. C. monogyma, P. mahaleb are closely related with similar habits and overlapping home ranges in Europe. Crataegus monogyna is very invasive in northern New South Wales, having spread rapidly and conspicuously throughout the region and elsewhere in southern Australia at rates of 80–120 m yr−1. Prunus mahaleb is far less invasive, being restricted to a small population, which is expanding at 20 m yr−1. Demographic analysis showed that potential growth rates of P. mahaleb (1.713–1.490) are greater than those for C. monogyna (1.138–1.103). Assessment of the seed dispersal ecology of both species revealed that C. monogyna had seeds dispersed by one bird and three mammals over many kilometers. P. mahaleb had seeds dispersed by six birds and four mammals over distances generally < 100 m. The role of humans in introducing both species and the characteristics of seed dispersal are more influential than demography in determining invasiveness. The more invasive Asparagus asparagoides has smaller fruit with a bicoloured display up to 1.5 m above ground. Less invasive A. declinatus has larger, translucent white fruit displayed at heights < 0.5 m above ground. The role of humans has also been important in shaping the course of invasion. Sensitivity analysis confirms that land management practices, which affect Olea europaea seedling establishment and survival, are most important at a landscape scale in determining invasiveness. The main factors determining the difference in invasiveness relate directly to the changing nature of human management of each species and the ecological interactions between the plants and the invaded environment. This research has implications for the prediction and management of biological invasions; emphasizing the importance of seed dispersal and human activities in determining the course of invasions: both of which cannot be readily predicted.

Asparagus asparagoides (bridal creeper) is a highly invasive noxious environmental weed in southern Australia. It poses a severe threat to biodiversity and conservation in temperate natural ecosystems. Pterostylis arenicola, a threatened terrestrial orchid endemic to South Australia, is directly imperilled by this weed in most of its remnant populations. The coincident growth phenologies of orchid and weed make for an ecologically sensitive environment when considering methods of weed control or eradication. To minimise impact on the orchid and its ecosystem, this paper examines the efficacy of herbicide application for A. asparagoides control using the weed wiping technique, comparing it to the conventional spray application method. The most prolonged control of A. asparagoides was achieved after a single wipe-application of 1.5 g a.i. (active ingredient) L−1 metsulfuron methyl, either alone or in combination with 120 g a.i. L−1 glyphosate, both treatments giving significantly better weed control five years after treatment than comparable spray applications. An investigation of the effect of glyphosate on cultures of the mycorrhizal fungus isolated from P. arenicola indicated a significant decline in mycelial growth with increasing herbicide concentration over the range 0.5–3.0 kg a.i. ha−1. These results provide further incentive for the use of ecologically sensitive herbicide application techniques, such as weed wiping, in areas of high conservation concern.

The diffusion of the environmental weed Bridal Creeper, Asparagus asparagoides, was investigated in south-western Australia. The primary aim was to identify native passerines dispersing the weed and to determine whether the weed’s current density distribution was correlated to the flight patterns of dispersal agents. The secondary aim was to test whether modelling techniques developed for assessing the diffusion of animal pests and diseases were suitable for estimating diffusion of a bird-dispersed environmental weed. Diffusion of A. asparagoides in south-western Australia mostly involved the Silvereye, Zosterops lateralis. Over 60% of weed distribution records with the greatest density were less than 50 m from source infestations. Gut passage rates of Z. lateralis and estimates of its flight speed showed that the maximum potential dispersal distance was approximately 12 km. Modelling showed significant differences between dispersal curves generated from current weed density distribution records (c. 77 m) and those generated from Z. lateralis flight pattern data (c. 90 m). Differences may have resulted from weed distribution/density maps not taking into account dispersal beyond the boundaries of fragmented habitats. The distribution of habitats favoured by Z. lateralis may influence the pattern of diffusion and rate of spread of the weed.

Surveys in South Africa for potential biological control agents for Asparagus asparagoides, an environmental weed in Australia, revealed the presence of an undescribed leafhopper (Cicadellidae: Typhlocibinae: Zygina sp.). This paper examines the biology, distribution, and host specificity of Zygina sp. to ascertain its potential as a control agent. Eggs are deposited beneath the epidermis of mature phylloclades and nymphs feed predominantly on the underside of phylloclades. Zygina sp. has five nymphal instars which require means of 37.5 ± 0.5, 20.6 ± 0.2, and 12.2 ± 0.2 days to develop to adults at 15, 20, and 30°C, respectively. Nymphs and adults caused extensive damage to phylloclades at these temperatures. Adults survive more than 150 days on A. asparagoides plants but less than 5 days if given only water. Natural enemies include strepsipterans, mites, and mymarid egg parasitoids. Host-specificity testing in the laboratory and data from field surveys revealed that Zygina sp. feeds on closely related species, especially within the Asparagaceae, although eggs are laid on only a few species which, with A. asparagoides, were previously included in the genus Myrsiphyllum. Zygina sp. occurs throughout the range of its preferred hosts in South Africa, inhabiting winter-, even-, and summer-rainfall areas. The results indicate that Zygina sp. has potential as a control agent for A. asparagoides in Australia.

At the species level, weeds have been primarily responsible for the presumed extinction of four Australian plant species and have the potential to force many more native plants to extinction. We discuss two known examples and describe research in progress on several endangered native plant species in relation to the threat posed by the non-native weed Bridal creeper (Asparagus asparagoides). At the ecosystem level, weeds may modify the functioning of natural ecosystems, usually negatively but sometimes positively, depending on the group of organisms being considered. Two Australian weed invasions that have positive, neutral and negative impacts on the invaded ecosystems are discussed. Of the various threats to native plant biodiversity, we conclude that increasing fragmentation of natural vegetation is a major factor that allows weeds to establish and dominate and thereby threaten still further the continued existence of native plant species and the Australian ecosystems in which they occur.

Asparagus officinalis is important horticultural species. Genus Asparagus includes some ornamental species and some medicinally important species, and distributed on dry land in the Old World. To clarify the phylogenetic relationships within this genus, we compared the restriction sites of chloroplast DNAs(ctDNAs)among ten species: A. officinalis. A. cochinchinensis. A. schoberioides, A. asparagoides, A. falcatus, A. macowanii, A. plumosus, A. scandens, A. virgatus and A. sprengeri. Phylogenetic relationships within this genus, derived from the ctDNA restriction sites, yielded values for inter-specific divergence (100 × p) that ranged from 0.4 to 2.4. Compared to other groups, such as Zea (0.0 to 0.3) and Aegilops /Triticum (0.24 to 1.0), the species of Asparagus exhibited higher levels of variation in their ctDNA. A phylogenetic tree showed that the Asparagus species used in this study could be divided into two clusters. The phylogenetic relationships derived from variations in the ctDNA were slightly different from those proposed by Bailey(1944) and Clifford and Conran(1987). The ctDNAS of A. falcatus (tetraploid, 2n=40) and A. sprengeri(hexaploid, 2n=60)gave the same restriction pattern, indicating that these species are very closely related. Moreover, it is of considerable interest that the polyploid species of Asparagus were grouped in one cluster. The three dioecious species, A. ofncinalis, A. schoberioides and A. cochinchinensis, were also grouped into one cluster, which suggests the possibility that dioecy in Asparagus might have had a monophyletic origin.

Medeola asparagoides Linnaeus, Species Plantarum 1: 339. 1753. "Habitat in Aethiopia." RCN: 2616. Lectotype (Jessop in Bothalia 9: 82. 1966): [icon] "Asparagus Africanus, scandens, Myrti folio et Myrti folio angustiore" in Tilli, Cat. Pl. Hort. Pisani: 17, t. 12, f. 1, 2. 1723. Current name: Asparagus asparagoides (L.) W. Wight (Liliaceae/Asparagaceae). Note: See Kleinjan & Edwards (in S. African J. Bot. 65: 28. 1999) who note that the type figure is inadequate to distinguish between the forms of the taxon that they recognise., Published as part of Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part M), pp. 651-689 in Order out of Chaos. Linnaean Plant Types and their Types, London :Linnaean Society of London in association with the Natural History Museum on page 659, DOI: 10.5281/zenodo.291971

Puccinia myrsiphylli is reported for the first time on weed infestations of Asparagus asparagoides in New Zealand, where it is concluded to have been introduced either accidentally or autonomously by way of wind-dispersed spores. A detailed description, illustration and genetic sequence of the specimen are provided.

A form of the South African plant, Asparagus asparagoides, has become a severe environmental weed in Australia, where it is known as bridal creeper. During surveys conducted in South Africa, information was gathered on the distribution, host range and phenology of the rust fungus, Puccinia myrsiphylli, to assess its suitability as a biological control agent for bridal creeper. The distribution of the rust encompasses all rainfall regions of South Africa. In the winter-rainfall region, the rust was first recorded on A. asparagoides in autumn and then increased in abundance until highest levels were reached in spring, just before the foliage senesced. A similar but less distinct phenology was recorded in the region where rainfall is not restricted to any particular season (aseasonal). The rust fungus was recorded in summer-rainfall regions, but sampling was not frequent enough there to determine its phenology. Strains of P. myrsiphylli were found on five other Asparagus species. Further research is required to determine whether these strains should be separated into different species. P. myrsiphylli was common on the widespread form of A. asparagoides (the form that occurs in Australia), but was never recorded in the field on a second form of A. asparagoides that is restricted to the south-western Cape, supporting the suggestion that the two forms may be different species. Furthermore, Aecidium schlechterianum, Aecidium myrsiphylli and Uredo myrsiphylli are newly listed as anamorphs of Puccinia myrsiphylli.

Fourteen taxa of the genus Asparagus were screened for their resistance to Stemphylium leaf spot under controlled conditions in growth chambers. The plants were inoculated with a conidial suspension of 2 isolates of Stemphylium sp. from asparagus. Disease assessment, based on percentage stem area necrotic, was made 13–17 days after inoculation. A. officinalis L. var. pseudoscaber (Grec.) Asch. & Graebn. and the 2 cultivars of A. officinalis L., Rutgers Beacon and Mary Washington, showed high levels of infection. Most other taxa showed low levels of infection. Seven of these were classed as highly resistant: A. asparagoides (L.) W.F. Wight, A. compactus Salter, A. densiflorus (Kunth) Jessop cv. Myers, A. densiflorus (Kunth) Jessop cv. Sprengeri, A. larcinus Burch., A. verticillatus L., and A. virgatus Bak. These species are considered to be potential sources of resistance for breeding commercial cultivars resistant to Stemphylium leaf spot.

Two forms of Asparagus asparagoides (L.) Wight are recorded from southern Africa, a widespread form, referred to as bridal creeper, which also occurs as an invasive weed in Australia, and a form restricted to the winter-rainfall region of the Western Cape, referred to as the south-western Cape form. The precise distribution, habitat associations and phenology of bridal creeper in southern Africa are described.