Mimosa pigra L. is a serious weed of wetlands of Australia, Asia and Africa. A suite of established biocontrol agents have been introduced in Australia and some Asian countries, but better control is needed. Nesaecrepida infuscata (Schaeffer) (Coleoptera: Chrysomelidae) is a common insect on M. pigra in tropical America. The larvae develop on the roots while the adults feed on the leaves. As both roots and leaves of M. pigra are relatively undamaged in the introduced range, this species has potential to limit the growth, survival and seed production. Furthermore, it is abundant in the dry season and so inflicts damage when most other agents are not active. In host specificity tests, larvae did not develop on any of the 65 test plant species other than M. pigra. Adult feeding on test plant species other than M. pigra was minimal. Based on these results, this insect has been released in Australia.

Abstract Mimosa pigra peel was sun‐dried for 2 days and then ground before being boiled with 30%w/v sodium hydroxide (NaOH) at 100°C for 3 h, washed and then dried at 55°C to constant weight. The cellulose was then synthesized using different NaOH concentrations and monochloroacetic acid (MCA) in isopropyl alcohol (IPA). Effects of various NaOH concentrations on degree of substitution (DS), viscosity and thermal of carboxymethyl cellulose from Mimosa pigra peel (CMCm) were investigated. The increasing of NaOH concentration resulted in increasing DS and viscosity. However, viscosity of CMCm decreased as temperature increased. Thermal properties were studied using differential scanning calorimetry (DSC). The melting point of the samples decreased as %NaOH increased. The effects of various NaOH concentrations in CMCm synthesis on the mechanical properties and water vapor permeability (WVP) of the CMCm films were investigated as well. With increasing NaOH concentrations (30–50%) were also found to result in improved mechanical properties. However, when the level of NaOH concentration was 60%, the mechanical properties of the CMC films decreased. This result indicates that the highest mechanical properties were found for 50% NaOH‐synthesized CMCm films. The WVP of the CMCm films increased as %NaOH increased. In addition, the CMCm films were tested to determine the effect of glycerol as a plasticizer on the mechanical properties. Increasing the amount of glycerol showed an increase in elongation at break but also led to a decrease in tensile strength. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

O objetivo deste estudo foi determinar a frequência relativa e o nível de infestação de cada espécie da flora aquática presente no reservatório de Salto Grande, Americana-SP. O levantamento e a identificação das plantas aquáticas foram realizados percorrendo-se as margens do reservatório em uma embarcação. Ao longo dele foram estabelecidos 20 pontos de avaliação, sendo todos eles fotografados e georreferenciados. Foram atribuídos valores de 0 a 100% tanto para as espécies presentes como para os espaços livres de macrófitas aquáticas que eventualmente pudessem ocorrer dentro dos pontos amostrados. Com os dados referentes ao número de indivíduos e pontos avaliados, foi determinada a frequência relativa de cada espécie. Foram identificadas 13 espécies em todo o reservatório, sendo 12 vasculares e uma de alga-verde (Chlorella spp.). Entre as espécies vasculares, nove eram plantas emersas flutuantes, as quais poderiam estar ou não ancoradas no leito do reservatório: Alternanthera philoxeroides, Brachiaria subquadripara, Cyperus difformis, Echinochloa polystachia var. spectabilis, Eichhornia crassipes, Panicum rivulare, Pistia stratiotes, Salvinia auriculata e Typha angustifolia. Outras três espécies foram encontradas somente em solo firme alagado: Aeschynomene sensitiva, Hedychium coronarium e Mimosa pigra.

Biology, host specificity, release and establishment of Macaria pallidata and Leuciris fimbriaria (Lepidoptera: Geometridae), biological control agents of the weed Mimosa pigra

Thermogravimetric analysis of giant sensitive plants under air atmosphere

Non-isothermal pyrolysis characteristics of giant sensitive plants using thermogravimetric analysis

Mimosa pigra L. is a tropical/sub-tropical spiny shrub that is becoming invasive in several parts of Asia, Australia and Africa. It is spreading on several floodplains where it can form thick, impenetrable, one-species stands that exclude other plants and most animals - both terrestrial and aquatic. M. pigra has invaded the floodplain of the Kafue River - a significant tributary of the Zambezi - in Zambia, especially within the regularly flooded areas of Lochinvar National Park (LNP). Here it has spread from a small infestation of about 2 ha in the early 1980s to at least 29,000 ha by 2005 - and is still spreading. This invasion is occupying a significant proportion of the protected floodplain - in the national park, which is also a Ramsar Wetland of International Importance and an Important Bird Area - with significant exclusion and negative impacts on the local biodiversity and on tourism, conservation and floodplain use by livestock and fisheries. The spread of M. pigra has resulted in the disappearance of some lekking sites for the endemic and vulnerable Kafue lechwe antelope (Kobus leche kafuensis) and its displacement from LNP into areas where it receives less protection resulting in increased illegal off-take of this threatened sub-species. Additionally, dense M. pigra stands have occupied preferred habitat for water birds and its further spread is likely to result in a drastic collapse of water bird populations in LNP. In response, the Environmental Council of Zambia in collaboration with the Zambia Wildlife Authority and with the support of a UNEP/GEF Project has conducted physical and chemical control measures since 2007. Thus far, an area approximated at 501.6 ha (17.3% of the current M. pigra infestation in LNP) has been cleared, resulting in the return of some water birds and herbivores including the lechwe. This paper presents the current status of the Mimosa invasion, its impact on biodiversity and the current control measures being employed, with emphasis on clearance of the invasive Mimosa in the protected areas.

Abstract Peanut (Arachis hypogaea L.) is the most popular legume cultivated for food and cash in the Guinea and Sudan savannah ecologies of northern Ghana. A three-year survey was conducted between 2003 and 2005 to: (1) document the prevalence of weed species, (2) determine current cropping systems and weed management practices, and (3) assess the response of peanut to weed management practices. Flora with more than 5% dominance included: (1) the dicotyledonous weeds, Corchorus olitorius L. Commelina benghalensis L., Commelina diffusa Burm., f, Desmodium scorpluras (Sw.) Desv., Hyptis suoveolens Poit., Mimosa invisa Mart., Mimosa pigra L., Mitracarpus villosus (Sw.) DC., Oldenlandia corymbosa L., Phyllanthus amarus Schum. & Thonn., Scoparia dulcis L., Tridax procumbens L., Triumfeta cordiflora A. Rich., and Vernonia galamensis (Cass.) Less.; (2) the monocotyledonous weeds Axonopus compresus (Sw.) P. Beauv., Cyperus esculentus L., Cyperus rotundus L., Digitaria horizontalisWilld., Eragrostis tremula Hochst. Ex Steud., Hackelochloa granularis (L.) O. Ktze., Kyllinga erecta Schumach. Var., Kyllinga squamulata Thonn. Ex Vahl., Paspalum scrobiculatum L., Rottboellia cochinchinensis (Lour.) Clayton, and Setaria pallide-fusca (Schum.) Stapf. & C.E. Hubbard; and (3) the parasitic weed Striga hermonthica (Del.) Benth. Land preparation practices included the use of tractors, followed by use of livestock, and lastly hand preparation. Cropping systems consisted of cereals preceding peanut, peanut preceding peanut, and intercropping peanut with sorghum (Sorghum bicolor L. Moench.), millet (Pennisetum Americanum L.), or corn (Zea mays L.). Genetically-improved peanut cultivars expressing bunch or erect growth habits were the most common cultivars although some farmers planted local cultivars expressing a distinct runner growth habit. The majority of farmers planted peanut from early June to early July based on rainfall pattern. Eighty-eight percent of peanut fields were hand weeded once, 3 to 5 weeks after planting (WAP) or twice, 2 to 3 and 5 to 6 WAP. Weed management was generally poorly timed and insufficient to prevent significant weed interference resulting in total oven-dried weed biomass ranging from 600 to 2400 kg/ha at harvest. Peanut haulm production ranged from 500 to 5500 kg/ha with improved cultivars. Pod yield production ranged from 200 to 1680 kg/ha. Results from this survey revealed the need for accelerated research and capacity building of farmers and agricultural extension agents for improved technology transfer to the peanut industry in the region.

# Invasive plants have negative impacts on ecosystems worldwide. Several ecological studies have identified disturbance as a causative mechanism of plant invasions. Changes to natural disturbances and/or newly imposed disturbances can favour an invader over native species especially those that are better adapted to prior conditions. # 2. To link the disturbance ecology of invasives to their management, we investigated the benefit of incorporating actions that manipulate disturbance (natural or imposed) into control efforts. We developed a simple model that describes the dynamics of an invader whose establishment is preferentially favoured by disturbance. # 3. The model includes the probability of disturbance differentially affecting sites occupied by natives and invaders. Invaded sites are disturbed by alternative control measures, which act to kill and/or remove above-ground biomass and reduce the seed bank. We couched the model in a decision theory tool, stochastic dynamic programming, and applied it to the management of Mimosa pigra, a pan-tropical invasive perennial shrub. # 4. We found that targeting the above-ground biomass of the invader (current population) was optimal when the probability of disturbance of native sites and the invader seed bank size were low to moderate. When both the rate of disturbance of native sites and invader seed banks were high, the best measure was that with the highest probability of reducing the seed bank (future populations). This measure was optimal despite its trade-off of having the highest probability of reinvasion. # 5. Synthesis and applications. Manipulation of disturbance regimes in both native and invaded sites can simplify control efforts. If there is a high probability that native vegetation will be disturbed, then management efforts should focus on future populations by attempting to reduce the size of the invader seed bank. This complicates control, as seed bank size is difficult to measure and reducing it requires intensive actions, which are likely to also negatively affect the seed bank of native species. If, however, the probability of disturbance of native sites can be reduced, practitioners can shift control from future populations to the current population, which is more straightforward to implement and monitor

The performance of growing rabbits fed Ruzi grass (Brachiaria ruziziensis), head lettuce (Lactuca sativa) residue, Mimosa pigra and water spinach (Ipomoea aquatica) was studied in an experiment using 64 rabbits (4 males and 4 females per treatment) of 2 breeds, New Zealand White and a crossbred between New Zealand White and native breed. The rabbits had an average initial weight of 668 g, were about 6 weeks old and were housed in individual pens. The foliages were fed ad libitum and a commercial concentrate was fed at a restricted level of 2% of body weight on a dry matter (DM) basis. In the digestibility experiment, the rabbits, 4 per foliage and males only, were fed the same foliages as in the growth experiment but without concentrate. Daily weight gain was lower in the group fed Ruzi grass, 14.8 g/d (p<0.001) compared to 17.6, 18.5 and 18.4 g/d for head lettuce, Mimosa pigra and water spinach, respectively. Feed intake and feed conversion ratio were lowest for the rabbits fed water spinach, 66 g DM/d and 3.6 kg DM/kg live weight, respectively. The New Zealand White breed had a higher daily gain than the crossbred rabbits (p<0.05), 18.0 and 16.7 g/d, respectively. There were no significant differences in feed intake, growth or feed conversion ratio due to sex. The digestibility coefficients of DM, organic matter, crude protein, crude fiber, neutral detergent fiber and acid detergent fiber were significantly lower (p<0.001) in the rabbits fed Ruzi grass. Breed and sex had no effect on digestibility. In conclusion, feeding head lettuce residue, Mimosa pigra and water spinach resulted in higher growth rate and digestibility than feeding Ruzi grass and can be recommended as alternative feeds.

Chloroform and ethyl acetate extracts of Aspergillus fischeri TISTR 3272 showed good growth inhibitory activity on Mimosa pigra and Echinochloa crus-galli. Bioassay-directed fractionation of the active extracts led to the isolation of five known compounds, (+)-terrein (1), (−)-6-hydroxymellein (2), two diketopiperazines (cyclo-(S-Pro-S-Leu) (3) and cyclo-(S-Pro-S-Val) (4)) and butyrolactone I (5). Compounds 2–5 were reported for the first time in this fungus. Their structural determinations were based on analyses of spectroscopic data and their weed growth inhibitory effects were assessed.

An alien species, which becomes established in natural or semi-natural ecosystems or habitas, is an agent of change and threatens native biological diversity. The Convention on Biological Diversity (CBD) declared in 1992, in which the issue on invasive alien species was raised, was ratified by the Indonesian Government in 1994. Protecting our biodiversity will be our moral obligation to comply with CBD. Inventory on the invasive alien plant species in Indonesia should be done by field surveys aside from the data collected from the references and herbarium specimens. Field studies should be carried out to get complete figures, to identify the new ones, to determine their distributions, to plan their management including prevention to spread, containment and movement or mitigate their impact to environment. Sometimes it is difficult in determining whether the plants are aliens or not. Cooperation with botanists and taxonomists in other parts of the world is necessary. There are some species of invasive aliens plant in Indonesia, which have to be watched for their aggressiveness i.e. Acasia nilotica (L.) Willd. ex Del., Eupatorium sordidum Less., Jatropa gossipifolia L., Mikania micrantha Kunth, Mimosa pigra L., Opuntia sp., and Piper aduncum L. have to be watch for their aggressiveness. Notes on some important invasive alien plant species are discussed.

Nontarget effects of a weed biological control agent on a native plant in Northern Australia

A new biological control agent for the weed &lt;I&gt;Mimosa pigra&lt;/I&gt; in Australia's northern wetlands

This study investigated the impacts of the biocontrol agent Malacorhinus irregularis Jacoby (Coleoptera, Chrysomelidae) on the weed Mimosa pigra L. (Mimosaceae). We used controlled experiments to determine whether larvae of different developmental stages can destroy mimosa seedlings, whether larvae can survive and develop when feeding on root nodules, whether larvae prefer root nodules or seedlings, and the importance of N2 fixation to mimosa. One third instar larva destroyed a mean of 1.6 seedlings overall, although this varied with larval density. First instar larvae spent more time on seedlings than on nodules, but final instar larvae spent more time on nodules. Larvae survived and developed on root nodules and on seedlings. Mimosa plants growing in pots only produced high numbers of root nodules when growing in low N conditions, indicating that mimosa responds to soil low N status by increasing symbiotic N2 fixation. The higher N content in mimosa leaves than leaves of native plants from north Australian wetlands, and the ability to vigorously nodulate in conditions with a low N supply suggest that mimosa relies on N2 fixation during times of low soil N availability and at sites with low N status. We propose that Malacorhinus below ground herbivory on root nodules and seedlings complements the above ground herbivory of other established biocontrol agents against mimosa.

Mimosa pigra L. is one of the most troublesome weeds in northern Australia, and is the target of a large biological control program, with 14 agents released to date. This paper describes surveys conducted between 1997 and 2004, for eight of these biological control agents. Surveys assessed the establishment of key agents. Both distribution and abundance of the most damaging agent, the stem-borer Carmenta mimosa Eichlin and Passoa (Lep.: Sesiidae), increased during the eight year period and the moth is now present in all catchments with major M. pigra infestations. The tip-borer, Neurostrota gunniella Busck (Lep.: Gracillariidae) is present in all M. pigra infestations, attacking 94% of tips. The leaf and flower-feeder, Coelocephalapion pigrae Kissinger (Col., Curculionidae) is widespread and its abundance is stable. Neither Acanthoscelides puniceus Johnson (Col., Bruchidae) nor Chlamisus mimosae Karren (Col., Chrysomelidae) were widespread or abundant when surveys commenced and populations declined during the survey period. The nocturnal beetle Malacorhinus irregularis Jacoby (Col., Chrysomelidae) was not found during these surveys, but later searches using different methods found it at three sites. Six other agents appeared not to have established, or are present at densities too low to be detected. How the results of these surveys affect management of M. pigra, and projections for future impacts against this weed are discussed. Using survey results and published literature we concluded that (1) seed and flower feeders must be capable of surviving periods of low food availability; (2) some climate matching may be beneficial before fungal biocontrol agents are released and (3) even in well studied systems such as M. pigra, the failure of an agent to establish cannot always be explained.

Abstract The effect of manual defoliation, and real and simulated herbivory by the leaf‐feeding moth Macaria pallidata on the growth and biomass of Mimosa pigra seedlings was assessed to determine the likely success of defoliating herbivores as biocontrol agents against the weed. Manual removal of at least half of all leaf material, maintained over a 6‐week period, significantly suppressed plant growth, as did a single week of herbivory by M. pallidata larvae. This suggests that M. pallidata and other defoliators have the potential to be highly successful agents in the biological control program for M. pigra.

Failure of Diabole cubensis, a promising classical biological control agent, to establish in Australia

Fourteen strains were isolated from nitrogen-fixing nodules on the roots of plants of the genus Mimosa growing in Taiwan, Brazil and Venezuela. On the basis of 16S rRNA gene sequence similarities, all of the strains were previously shown to be closely related to each other and to belong to the genus Burkholderia. A polyphasic approach, including DNA-DNA reassociation, whole-cell protein analysis, fatty acid methyl ester analysis and extensive biochemical characterization, was used to clarify the taxonomic position of these strains: all 14 strains were classified as representing a novel species, for which the name Burkholderia mimosarum sp. nov. is proposed. The type strain, PAS44(T) (=LMG 23256(T) =BCRC 17516(T)), was isolated from Mimosa pigra nodules in Taiwan.

Singapore is a recognized global hotspot for invasive species and many introduced plant species have become major weeds there. Some of the common invasive taxa, such as Asystasia gangetica ssp. micrantha , Mimosa pigra , Neptunia plena , Panicum maximum , and Urochloa mutica , are spread over large areas and dominate the indigenous flora in some habitats. In a study aimed at understanding the relationship between polyploidy and invasiveness, we show that all the investigated invasive taxa are polyploids. A. gangetica ssp. micrantha , N. plena , and P. maximum vary in chromosome number and ploidy level across the world, but we recorded only one chromosome count for each of these species in Singapore. Similarly, the cytology of M. pigra and U. mutica also revealed that these species are polyploid, each with only one chromosome number across all populations. The results indicate that one polyploid line in each of these species has been selected favourably and has become invasive. We also show that all the species exhibit normal male meiosis and possess high percentages of pollen fertility. Based on the present study and an analysis of previously reported ploidy levels, we suggest that these taxa are probably of allopolyploid origin. We conclude that polyploidy and an effective reproductive system are a perfect mix for successful invasion by these species in Singapore. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 395‐403.