Advances in green nanotechnology: Data for green synthesis and characterization of iron nanoparticles synthesized using Galinsoga parviflora, Conyza bonariensis and Bidens pilosa leaf extracts, and their application in degradation of methylene blue dye and rifampicin antibiotic.

This data article reports contents of the information derived from an efficient, environmentally friendly, and low-cost method of synthesis and recovery of iron nanoparticles using Galinsoga parviflora, Conyza bonariensis and Bidens pilosa aqueous leaf extracts as reducing, stabilizing, and capping agents, and applications of the nanoparticles in degradation of organic dyes and antibiotics. Various spectroscopic and microscopic techniques were used to collect the data. Data is displayed in the form of .raw files, graphs, images, Microsoft Excel sheets, .data point files, and PDF files, along with other formats. Data analysis and interpretation methods have also been presented. Researchers, research students, academicians, and industrialists can benefit greatly from the data in order to gain knowledge about the green synthesis of iron nanoparticles and related applications such as degradation organic pollutants. The data is deposited in the mendeley data repository as two independent datasets at https://data.mendeley.com/datasets/rxkv6j7hrx.

Evaluation of anti-amnesic effect of Conyza bonariensis in rats.

OBJECTIVE: Conyza bonariensis is an ornamental medicinal weed. This experiment was planned to explore the outcome of petroleum ether extract of C. bonariensis (PECB) leaves on scopolamine-induced amnesia in rats. MATERIALS AND METHODS: For impairing memory, 0.4 mg/kg (i. p.) of scopolamine was given. Fifty to 200 mg/kg of PECB was fed orally to rats and 3 mg/kg (i. p.) of tacrine was given as a standard drug. Anti-amnesic property was evaluated in Barnes maze using ANY-maze software. Following a behavioral study, acetylcholinesterase (AChE), ß-amyloid1-41, antioxidant enzymes, and cytokine levels were measured. Furthermore, reverse transcription-polymerase chain reaction was done for expression of the marker genes such as AChE, Nrf2, NF-κB, PP2A, and HO-1, whereas BDNF, TrkB, caspase-3, and Bax were measured by Western blotting. RESULTS: PECB and tacrine significantly improved memory dysfunction by decreasing escape latency in Barnes maze. At the highest dose, treatment with PECB altered the scopolamine-induced hyperactivation of AChE and ß-amyloid1-41 activity. PECB elevated the levels of superoxide dismutase, glutathione, and catalase and decreased lipid peroxidation and nitric oxide dose dependently. PECB attenuated scopolamine-induced increase of tumor necrosis factor-α and interleukin (IL)-1ß concentrations in the hippocampus with reversed diminished IL-10 level toward normal in the brain. Nrf2, HO-1, PP2A, BDNF, and TrkB were significantly upregulated with downregulation of AChE, NF-κB, Tau, Bax, and caspase-3. Different components such as beta-amyrin and alpha-amyrin were isolated from leaves of the plant. CONCLUSION: The results indicated that PECB might be a potential curative drug for the treatment of cognitive impairment.

Molecular Mechanisms Responsible for In Vitro Cytotoxic Attributes of Conyza bonariensis Extract against Lymphoblastic Leukaemia Jurkat Cells.

BACKGROUND: Conyza bonariensis is known to have anti-cancer properties. OBJECTIVE: The current study investigated the in vitro pro-apoptotic properties of Conyza bonariensis (C. bonariensis) towards human lymphoblastic leukemia Jurkat cells. METHODS: Ariel parts of C. bonariensis were macerated in a non-polar (n-Hexane) solvent. MTS cell viability assay was employed to determine the cytotoxic activity of the extract towards human leukemia Jurket cells and normal Peripheral Blood Mononuclear Cells (PBMCs). The phytochemical composition of the extract was screened using HPLC method. Flow cytometric studies (FACS) were conducted to explore the pro-apoptotic potential of the extract. Western blot studies were employed to identify the molecular targets involved in the induction of apoptosis. RESULTS: The n-hexane extract showed selective cytotoxic activity towards Jurkat cells. FACS analysis indicated that the extract induced early and late apoptosis in Jurkat cells. Western blot studies revealed that the extract downregulated the expression of DNMT1, SIRT1, and UHRF1 with a simultaneous up-regulation of p73 and caspases-3 proteins expression. HPLC characterization of the extract revealed the presence of phenolic compounds. CONCLUSION: Overall, these findings demonstrate that the anti-cancer effects of a Conyza bonariensis extract towards human lymphoblastic leukemia Jurkat cells are due to the modulation of the activity of multiple oncogenic and tumor suppressor proteins. Phenolic contents of the extract are proposed to be responsible for these activities.

Conyza bonariensis as an alternative host for Colletotrichum species in Argentina.

AIMS: This study investigated the diversity of Colletotrichum isolates recovered from Conyza bonariensis leaves through the use of morphological characteristics, growth rate, carbon sources utilization and phylogenetic analysis. METHODS AND RESULTS: In all, 30 Colletotrichum isolates recovered from C. bonariensis leaves showing symptoms of disease were included in the present study. Based on the analysis of morphology and sequences, the isolates were distributed into six Colletotrichum species complexes. The concatenated alignment of GAPDH and ITS sequences showed that 20 out of 30 isolates were included in four species complexes which comprise the most important pathogens causing anthracnose in soybean or anthracnose and stalk rot in maize: C. truncatum, C. orchidearum, C. gloeosporioides and C. graminicola. The remaining 10 isolates were included in the C. boninense and C. destructivum species complexes or could not be assigned to any complex with the available information. CONCLUSION: Weeds belonging to genus Conyza are host to soybean and maize potential pathogenic species of Colletotrichum and could have a role as inoculum reservoir for cross contamination in the agroecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: The combined use of morphological, kinetics and physiological parameters of growth and phylogenetic analysis in Colletotrichum isolates from Conyza leaves allowed the detection of species complexes previously not identified in Argentina.

Essential Oil Compositions of Three Invasive Conyza Species Collected in Vietnam and Their Larvicidal Activities against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus.

Mosquito-borne infectious diseases are a persistent problem in tropical regions of the world, including Southeast Asia. Vector control has relied principally on synthetic insecticides, but these have detrimental environmental effects and there is an increasing demand for plant-based agents to control insect pests. Invasive weedy plant species may be able to serve as readily available sources of essential oils, some of which may be useful as larvicidal agents for control of mosquito populations. We hypothesize that members of the genus Conyza (Asteraceae) may produce essential oils that may have mosquito larvicidal properties. The essential oils from the aerial parts of Conyza bonariensis, C. canadensis, and C. sumatrensis were obtained by hydrodistillation, analyzed by gas chromatography-mass spectrometry, and screened for mosquito larvicidal activity against Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. The essential oils of C. canadensis and C. sumatrensis, both rich in limonene (41.5% and 25.5%, respectively), showed notable larvicidal activities against Ae. aegypti (24-h LC50 = 9.80 and 21.7 µg/mL, respectively) and Ae. albopictus (24-h LC50 = 18.0 and 19.1 µg/mL, respectively). These two Conyza species may, therefore, serve as sources for alternative, environmentally-benign larvicidal control agents.

Phytosynthesis of nearly monodisperse CuO nanospheres using Phyllanthus reticulatus/Conyza bonariensis and its antioxidant/antibacterial assays.

In the present article we have developed an eco-friendly, phytosynthetic, cost-effective and straightforward method for the synthesis of nearly monodisperse CuO nanospheres (NSP) using leaf extracts of medicinal plants Phyllanthus reticulatus (PR) and Conyza bonariensis (CB) as novel green reducing agents. Copper nitrate (Cu (NO3)2) was used as a precursor. The stoichiometric ratio of both leaf extracts (PR/CB) and Cu(NO3)2 was standardized for the synthesis of NSP. During formation of CuO NSP, a color of solution gradually changed from light greenish-blue to black with a number of intermediate stages and it correlated to the reduction reaction catalyzed by phytochemicals. As-synthesized materials were characterized in detail at the structural, electronic level and morphological authentication by XRD, FT-IR, EDS, UV-DRS, Raman, XPS, SEM, TEM, BET and AFM. SEM studies of phytosynthesized materials revealed nearly monodisperse nanospheres, while TEM rendered average particles size 4-14 nm. Also, AFM profiles suggested a homogenized nature of the nanospheres. Then, the antioxidant property was obtained by α, α-diphenyl-ß-picrylhydrazyl (DPPH). Ethanolic, methanolic extracts were used for the antioxidant activity, while ascorbic acid was used as a standard medium. Each plant extract exhibited noteworthy antioxidant activity. Moreover, the antibacterial activity of CuO NSP (PR/CB) was tested against human pathogenic bacteria viz. gram-positive Staphylococcus aureus, Klebsiella pneumoniae, and gram-negative Escherichia coli. Result rendered effective antibacterial activity against Escherichia coli.

Species Identification of Conyza bonariensis Assisted by Chloroplast Genome Sequencing.

Flaxleaf fleabane (Conyza bonariensis [L.] Cronquist) is one of the most difficult weeds to control worldwide. There are more than 150 Conyza species in the world and eight species in Australia. Correct identification of these species can be problematic due to their morphological similarities especially at seedling stage. Developing a robust genetics - based species identification method to distinguish C. bonariensis from other closely related species is important for early control of weeds. We thus examined the chloroplast (cp) genome of C. bonariensis, aiming to identify novel DNA barcodes from the genome sequences, and use the entire cp genome as a super-barcode for molecular identification. The C. bonariensis chloroplast genome is 152,076 bp in size, encodes 133 genes including 88 protein-coding genes, 37 tRNA genes and 8 ribosomal RNA genes. A total of 151 intergenic regions and 19 simple sequence repeats were identified in the cp genome of C. bonariensis, which provides a useful genetic resource to develop robust markers for the genetic diversity studies of Conyza species. The sequence information was used to design a robust DNA barcode rps16 and trnQ-UUG which successfully separated three predominant Conyza species (C. bonariensis, C. canadensis, and C. sumatrensis). Phylogenetic analyses based on the cp genomes of C. bonariensis, C. canadensis and 18 other Asteraceae species revealed the potential of using entire cp genome as a plant super-barcode to distinguish closely-related weed species.

Complete chloroplast genome of glyphosate resistant Conyza bonariensis (L.) Cronquist from Australia.

Conyza bonariensis, flaxleaf fleabane, is a serious weed in Australian agricultural systems, particularly the north-east cropping system. We present the complete chloroplast sequence of C. bonariensis reconstructed from Illumina whole genome shotgun sequencing. This is the first complete chloroplast genome available for genus Conyza. The complete chloroplast sequence is 153,014 bp long, and has the same gene content and structure as other members of the tribe Astereae. A Bayesian phylogeny of the chloroplast coding regions of 18 representatives of Astereae is presented. The C. bonariensis chloroplast genome is deposited at GenBank under accession number MF276802.

Development stages horseweed in soybeans competition / Estádios de desenvolvimento da buva em competição com soja

The objective of this study was to evaluate the relative competitive ability of soybean with different development stages of hairy fleabane. Two experiments were conducted in greenhouse, in a completely randomized design. In the experiment it was tested soybean and hairy fleabane competition at different stage of development (rosette and 15 cm height) at the proportions 100:0, 75:25, 50:50, 25:75 and 0:100, and total plant population was 315 plant m-2. The variables evaluated were plant height, leaf area, and shoot dry matter (leaves and stems). Competitive analysis was performed by diagrams and interpreting the competitiveness index. The soybean has greater competitive ability that horseweed for both development stages. The intraspecific competition is more intense for soybean when in hairy fleabane rosette stage, and the competitive relations are equivalent between soybean and hairy fleabane of 15 cm tall. The both hairy fleabane stages were injured in the soybeans competition.(AU)

O objetivo deste trabalho foi avaliar a habilidade competitiva relativa da cultura da soja com buva de diferentes estádios de desenvolvimento. Foram realizados dois experimentos em casa de vegetação, em delineamento inteiramente casualizado. Os experimentos testaram a competição de soja e buva (estádio roseta e plantas com 15 cm de estatura) nas proporções de 100:0, 75:25, 50:50, 25:75 e 0:100, com população equivalente a 315 plantas m-2. As variáveis avaliadas foram estatura, área foliar e matéria seca da parte aérea (folhas e caule). A análise da competitividade foi realizada por aplicação de diagramas e interpretações dos índices de competitividade. Os resultados da competição da soja com buva de diferentes estádios de desenvolvimento evidenciam que o cultivar de soja BRS Estância RR, em geral, possui mais habilidade competitiva que a buva, independentemente do estádio de desenvolvimento. A competição intraespecífica é mais intensa para a cultura quando em competição com buva em estádio de roseta, enquanto para a soja com buva de 15 cm as relações de competição se equivalem. O desenvolvimento da buva é prejudicado na competição com a soja.(AU)

Soybean yield loss and economic thresholds due to glyphosate resistant hairy fleabane interference / Perda de rendimento da soja e nível de dano econômico pela interferência de buva resistente ao glifosato

The interference of glyphosate resistant hairy fleabane (Conyza bonariensis) has caused yield losses in soybean crop. Knowledge of the economic threshold is an important aspect for the economic management of resistant weeds. Because of it, the interference of the glyphosate resistant hairy fleabane density on the soybean yield loss was evaluated, as well as to estimate the economic threshold. Two experiments were conducted to verify the effect of different weed densities on the yield of two soybean cultivars (BRS Estância and BMX Turbo). Weed density ranged from 0 to 124 plants m-2. The yield of the BRS Estância decreased by 1.4% to the increase of one single plant, while for the BMX Turbo the loss was 25.9%. Soybean yield and economic threshold were lower for the BMX Turbo cultivar compared to the cultivar BRS Estância, which can be attributed to the genotype, competitive ability, weed development stage and/or environment. Increases in crop yield expectation, soybean price and herbicide efficiency reduce the economic threshold, indicating that the adoption of control measures should be taken when the weed density is low. Due to the high cost of hairy fleabane control, it is only feasible at high densities.(AU)

A interferência de plantas de buva (Conyza bonariensis) resistente ao herbicida glyphosate tem causado perdas de produtividade na cultura da soja. O conhecimento do nível de dano econômico é um importante fator para o manejo econômico de plantas daninhas resistentes na cultura da soja. Para isso, foi avaliada a interferência da densidade de buva resistente ao glyphosate sobre a perda de rendimento da soja, bem como estimado o nível de dano econômico. Dois experimentos foram conduzidos para verificar o efeito de diferentes densidades da planta daninha sobre a produtividade de dois cultivares de soja (BRS Estância e BMX Turbo). As densidades de buva variaram de 0 a 124 plantas m-2. A produtividade do cultivar BRS Estância reduziu 1,4% ao aumento de uma planta, enquanto para o cultivar BMX Turbo a perda foi de 25,9%. A produtividade da soja e o nível de dano econômico foram menores para o cultivar BMX Turbo, em comparação com o cultivar BRS Estância, o que pode ser atribuído ao genótipo, à habilidade competitiva, ao estádio de desenvolvimento da buva e/ou a ambiente. Aumentos na expectativa de produtividade da cultura, no preço da soja e na eficiência dos herbicidas reduzem o nível de dano econômico, indicando que a adoção de medidas de controle deve ser tomada quando a população de buva é baixa. Em função do elevado custo de controle da buva, este somente é viável em altas densidades.(AU)

Biology and management of two important Conyza weeds: a global review.

Weed management is one of the prime concerns for sustainable crop production. Conyza bonariensis and Conyza canadensis are two of the most problematic, noxious, invasive and widespread weeds in modern-day agriculture. The biology, ecology and interference of C. bonariensis and C. canadensis have been reviewed here to highlight pragmatic management options. Both these species share a unique set of biological features, which enables them to invade and adapt a wide range of environmental conditions. Distinct reproductive biology and an efficient seed dispersal mechanism help these species to spread rapidly. Ability to interfere strongly and to host crop pests makes these two species worst weeds of cropping systems. These weed species cause 28-68 % yield loss in important field crops such as soybean and cotton every year. These weeds are more prevalent in no-till systems and, thus, becoming a major issue in conservation agriculture. Cultural practices such as crop rotations, seed rate manipulation, mulching, inter-row tillage and narrow row spacing may provide an effective control of these species. However, such methods are not feasible and applicable under all types of conditions. Different herbicides also provide a varying degree of control depending on crop, agronomic practices, herbicide dose, application time and season. However, both these species have evolved resistance against multiple herbicides, including glyphosate and paraquat. The use of alternative herbicides and integrated management strategies may provide better control of herbicide-resistant C. bonariensis and C. canadensis. Management plans based on the eco-biological interactions of these species may prove sustainable in the future.

Clotting and fibrinogenolysis inhibition by essential oils from species of the Asteraceae family

ABSTRACT Essential oils are pharmacologically active and unexplored compounds. The inhibitory properties of essential oils from Baccharis dracunculifolia, Conyza bonariensis, Tithonia diversifolia and Ambrosia polystachya were evaluated in the coagulation and fibrinogenolysis induced by snake venoms. The essential oil from Conyza bonariensis extended the clotting time of Lachesis muta from 52.2 to 115.2 seconds and that of Bothrops moojeni from 108.3 to 2340.0 seconds, when pre-incubated with the venoms. The longest clotting times for Bothrops atrox venom were observed after incubation with the essential oils from Conyza bonariensis and Tithonia diversifolia: the times increased from 100.8 to 264.0 and 227.7 seconds, respectively. The prior incubation of the essential oils with plasma and subsequent addition of Lachesis muta venom resulted in a pro-clotting effect. The oils from Ambrosia polystachya and Baccharis dracunculifolia caused 100% of inhibition on the fibrinogenolysis induced by Bothrops moojeni and Lachesis muta venoms (the oils were previously incubated with the venom). The results indicate that the essential oils show promise as adjuvants for the treatment of snakebites.

Efecto antiinflamatorio y antimicótico del extracto alcohólico y composición química del aceite de hojas de Conyza bonariensis (L) Cronquist (canilla de venado) / Anti-inflammatory and antimitotic effect of the alcoholic extract and chemical composition of the oil from Conyza bonariensis (L) Cronquist (deer shinbone) leaves

Introducción: la especie Conyza bonariensis (L.) Cronquist, comúnmente llamada canilla de venado, es de origen americano. Objetivos: contribuir al estudio farmacológico y toxicológico de los extractos alcohólicos y a la evaluación química del aceite de hojas de C bonariensis de Ecuador. Métodos: se emplearon 2 tinturas a 50 por ciento con etanol a 70 y 90 por ciento de hojas secas. Se realizó un estudio fitoquímico a través del sistema acoplado de cromatografía gaseosa-espectrometría de masas, se determinó el efecto antimicótico mediante inhibición de dilución en placa con siembra en superficie por diseminación, y antiinflamatorio en el modelo de edema de la oreja inducido por aceite de Croton en ratones albinos de la línea OF1. Resultados: el tamizaje fitoquímico mostró presencia de aceites esenciales, triterpenos-esteroides, compuestos fenólicos, flavonoides, quinonas, antocianidinas, saponinas y compuestos reductores. Se determinó estructuras a 32 componentes del aceite esencial extraído de las hojas y el sesquiterpeno: trans-b-farneseno resultó el componente mayoritario con 70,82 por ciento, este compuesto se informa por primera vez en esta especie. El extracto hidroalcohólico (25 µL a cada lado de las orejas tratadas) inhibió significativamente la inflamación comparado con bencidamina. Conclusiones: los extractos hidroalcohólicos mostraron efecto antiinflamatorio en las condiciones experimentales del estudio y se determinó la composición química del aceite de hojas de C. bonariensis

Introduction: the Conyza bonariensis (L) Cronquist species, usually called deer shinbone is of American origin. Objectives: to contribute to the pharmacological and toxicological study of alcoholic extracts and to the chemical assessment of C. bonariensis leaf oil from Ecuador. Methods: two 50 percent tinctures of 70 percent and 90 percent ethanol content in dry leaves were used. A phytochemical study was conducted by an combined system of mass spectrometry and gas chromatography; the amniotic effect was determined using plate dilution inhibition with surface culturing by dissemination, and the anti-inflammatory effect in the Croton oil induced ear edema model in OF1 line albino mice. Results: the phytochemical screening showed the presence of essential oils, triterpene-steroids, phenolic compounds, flavonoids, quinones, anthocyanidines, saponins and reducing compounds. The structures of 32 essential oil components extracted from the leaves were identified along with and the sesquiterpene trans-b-farnesene that was the major component (70.82 percent), this compound is reported for the first time in this species. The hydroalcoholic extract (25 µL on each side of the treated ears) significantly inhibited inflammation compared to benzidamine. Conclusions: hydroalcoholic extracts showed anti-inflammatory effect in the experimental conditions of the study and the chemical composition of C. bonariensis leaf oil was identified

Efecto antiinflamatorio y antimicótico del extracto alcohólico y composición química del aceite de hojas de Conyza bonariensis (L) Cronquist (canilla de venado) / Anti-inflammatory and antimitotic effect of the alcoholic extract and chemical composition of the oil from Conyza bonariensis (L) Cronquist (deer shinbone) leaves

Introducción: la especie Conyza bonariensis (L.) Cronquist, comúnmente llamada canilla de venado, es de origen americano. Objetivos: contribuir al estudio farmacológico y toxicológico de los extractos alcohólicos y a la evaluación química del aceite de hojas de C bonariensis de Ecuador. Métodos: se emplearon 2 tinturas a 50 por ciento con etanol a 70 y 90 por ciento de hojas secas. Se realizó un estudio fitoquímico a través del sistema acoplado de cromatografía gaseosa-espectrometría de masas, se determinó el efecto antimicótico mediante inhibición de dilución en placa con siembra en superficie por diseminación, y antiinflamatorio en el modelo de edema de la oreja inducido por aceite de Croton en ratones albinos de la línea OF1. Resultados: el tamizaje fitoquímico mostró presencia de aceites esenciales, triterpenos-esteroides, compuestos fenólicos, flavonoides, quinonas, antocianidinas, saponinas y compuestos reductores. Se determinó estructuras a 32 componentes del aceite esencial extraído de las hojas y el sesquiterpeno: trans-b-farneseno resultó el componente mayoritario con 70,82 por ciento, este compuesto se informa por primera vez en esta especie. El extracto hidroalcohólico (25 µL a cada lado de las orejas tratadas) inhibió significativamente la inflamación comparado con bencidamina. Conclusiones: los extractos hidroalcohólicos mostraron efecto antiinflamatorio en las condiciones experimentales del estudio y se determinó la composición química del aceite de hojas de C. bonariensis(AU)

Introduction: the Conyza bonariensis (L) Cronquist species, usually called deer shinbone is of American origin. Objectives: to contribute to the pharmacological and toxicological study of alcoholic extracts and to the chemical assessment of C. bonariensis leaf oil from Ecuador. Methods: two 50 percent tinctures of 70 percent and 90 percent ethanol content in dry leaves were used. A phytochemical study was conducted by an combined system of mass spectrometry and gas chromatography; the amniotic effect was determined using plate dilution inhibition with surface culturing by dissemination, and the anti-inflammatory effect in the Croton oil induced ear edema model in OF1 line albino mice. Results: the phytochemical screening showed the presence of essential oils, triterpene-steroids, phenolic compounds, flavonoids, quinones, anthocyanidines, saponins and reducing compounds. The structures of 32 essential oil components extracted from the leaves were identified along with and the sesquiterpene trans-b-farnesene that was the major component (70.82 percent), this compound is reported for the first time in this species. The hydroalcoholic extract (25 µL on each side of the treated ears) significantly inhibited inflammation compared to benzidamine. Conclusions: hydroalcoholic extracts showed anti-inflammatory effect in the experimental conditions of the study and the chemical composition of C. bonariensis leaf oil was identified(AU)

Plant diversity, herbivory and resistance of a plant community to invasion in Mediterranean annual communities.

Several components of the diversity of plant communities, such as species richness, species composition, number of functional groups and functional composition, have been shown to directly affect the performance of exotic species. Exotics can also be affected by herbivores of the native plant community. However, these two possible mechanisms limiting invasion have never been investigated together. The aim of this study was to investigate the relationships between plant diversity, herbivory and performance of two annual exotics, Conyza bonariensis and C. canadensis, in Mediterranean annual communities. We wanted to test whether herbivory of these exotics was influenced either by species richness, functional-group richness or functional-group composition. We also studied the relationship between herbivory on the exotic species and their performance. Herbivory increased with increasing species and functional-group richness for both Conyza species. These patterns are interpreted as reflecting a greater number of available herbivore niches in a richer, more complex, plant community. The identities of functional groups also affected Conyza herbivory, which decreased in the presence of Asteraceae or Fabaceae and increased in the presence of Poaceae. Increasing herbivory had consequences for vegetative and demographic parameters of both invasive species: survival, final biomass and net fecundity decreased with increasing herbivory, leading to a loss of reproductive capacity. We conclude that communities characterised by a high number of grass species instead of Asteraceae or Fabaceae may be more resistant to invasion by the two Conyza species, in part due to predation by native herbivores.