Biological control with plant pathogens is an effective, safe, selective and practical means of weed management that has gained considerable importance. Alligatorweed alternanthera philoxeroides, also spelled alligator weed, hails from south america but has been widely spread to the warmer regions of the united states. Do not try to control alligator weed without their expert assistance. Another aquatic weed, the giant salvinia salvinia molesta is a serious pest.
An excellent account of the early exploratory work and the later experi mental studies on alligatorweed and its natural enemies in south america is. Alligatorweed, alternanthera philoxeroides, an aquatic amaranth introduced into the united states from south america around the turn of the century, has become a noxious aquatic weed over the past 40 years. Alligator weed has a number of natural enemies in its native south america. Biological control of weeds in australia csiro publishing. The flea beetle provides excellent control of alligator weed in aquatic. Control and spread of alligator weed alternanthera philoxeroides mart. Weeds in australia alligator weed alternanthera philoxeroides australian government. Alligator weed facts learn how to kill alligatorweed.
Biological control of alligatorweed, alternanthera philoxeroides, the worlds first aquatic. Alligator weed weed biocontrol projects manaaki whenua. During the mid1960s the alligator weed beetle was successfully imported to control infestations of alligator weed in florida. An innovative method for the biological control of.
The need for control measures against alligator weed alternanthera. Biological control and ecology of alligator weed land. Biological control and ecology of cabomba and alligator weed. As stems potentially resprout at every node, regular checking of sites after control efforts is essential. Alligator weed poses an extreme threat to queenslands waterways, wetlands.
The effect of temperature on the development and survival. Getting rid of alligatorweed is the responsibility of any riparian or waterway manager. Pdf invasion of alternanthera philoxeroides alligator weed in. Alligator weed is one of the greatest threats to waterways, wetlands, floodplains and irrigation systems in australia. Three agents were released in the usa and two of them the flea beetle agasicles hygrophila and the moth arcola malloi were released in australia in the 1970s.
Download a page pdf from identification and biology of nonnative plants in floridas natural areas second edition 1. Chapter 1 alligatorweed biological control of invasive. Fungi commonly mistaken for biological control agents pdf file, 336. Agasicles hygrophila, a leaf feeding chrysomelid beetle, was introduced into new zealand in 1982 for the biological control of alligator weed, alternanthera philoxeroides. Biological control of alligatorweed alternanthera philoxeroides. Control was greatest for all herbicides at rates higher than the. The hollow stems provide considerable buoyancy of the mat buckingham 1996. A fungal pathogen was found in chongqing and sichuan. Alligatorweed disrupts water flow causing increased sedimentation.
Alligator weed alternanthera philoxeroides weed management guide pdf 359 kbabout the guide. The introduction of this insect into the united states was approved in 1963, but it was not successfully established on the invasive alligatorweed until 1965. Randall and mandy tu biological control biocontrol for short is the use of animals, fungi, or other microbes to feed upon, parasitize or otherwise interfere with a. There are currently no biological control methods of eradication rather than goats which can keep the plant under control by feeding on the weed. It has been classed as a weed because of its competitive advantage over our native flora. International symposium on biological control of weeds xii. The aquatic alligator weed flea beetle agasicles hygrophila, has been quite successful in controlling alligator weed growing in the water. Biological control of alternanthera philoxeroides, alligator weed, began when george vogt, usda, conducted several surveys in south america during the 1960s. Insects have been released for the biological control of a.
Control and spread of alligator weed alternanthera. Biological control agents for weeds in new zealand. This project continues the host testing of insects for the biological control of alligator weed and continues ecological studies to underpin development of better management strategies for the weed in australia. Several herbicides that now provide better control include. On the basis of current containment in urban gardens, we recommend that governments better mobilize the community e. Alligatorweed aquatic mississippi state university. Three insects appeared suitable for introduction into the united states as biological control agents of alligatorweed. In the earlier work, the researchers had identified, prioritised and started the host specificity testing of several potential invertebrate agents. Alligator weed control manual department of primary.
Alligator weed control manual nsw department of primary industries. Alligatorweed national invasive species information. Biological control of alligator weed alternanthera philoxeroides mart. The alligator weed control manual see other publications provides a comprehensive overview of the various chemical, physical and biological control options. Control effort that is poorly performed or not followed up can actually help spread the weed and worsen the problem. Cen11 1 september, 2008 land and water australia, defeating the weed menace programme. Alligator weed alternanthera philoxoroides weed management. Alligator weed can be mistaken for other species, such as lesser joy weed alternanthera denticulata, an australian native. Pdf progress of biological control of alligator weed in. Such predictions are being used in australia to predict spread and ef. This plant may be known by one or more common names in different places, and some are listed above. Plants profile for alternanthera philoxeroides alligatorweed.
Management of aquatic alligator weed alternanthera philoxeroides in an early stage of invasion daniel clements 1. In waterways, it can grow from plant fragments dispersed from a parent infestation and produce new infestations downstream. As a weed that can grow both on land and in water and can tolerate a range of control methods, alligator weed has serious impacts worldwide and in australia see nsw weedwise for information about alligator weed this control manual brings together. Alternanthera philoxeroides in new south wales, australia. Alternanthera philoxeroides, biological invasions, plantherbivore. The flea beetle provides excellent control of alligator weed.
Biological control of alligatorweed alternanthera philoxeroides with a fusarium sp. Physical removal of alligator weed is possible, but not usually 100% successful in eradicating the weed because the plant is able to regrow and propagate from stem fragments alone. An excellent account of the early exploratory work and the later experimental studies on. See table 1 in floridas established arthropod weed biological control agents and their targets 20 for a list of arthropod biological control agents that occur on this species. Two other insects, thrips and stem borers, were also imported. Alligator weed alternanthera philoxeroides summary alligator weed alternanthera philoxeroides is a perennial aquatic and semiaquatic plant native to tropical and subtropical south america. The act requires everyone to take all reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control. For example, whereas weed killing chemicals can also destroy fruitbearing plants, biological control allows the fruit to be left. Alligator weed alternanthera philoxeroides weeds of.
Alligatorweed roots in soil along shore or in shallow water but then grows across the. Alligator weed was introduced to the united states from south america. Until recently, herbicides have had very limited short term and no long term effectiveness. The alligatorweed flea beetle, agasicles hygrophila selman and vogt, was the first insect ever studied for biological control of an aquatic weed. Biological control and ecology of alligator weed shon schooler and mic julien project no. At this time there is no available biological control for alligator weed. Three biological control agents from south america have been introduced into. Successful biological control for mist flower ageratina. Effects of weather on the biological control of alligator weed in the lower mississippi valley region, technical bulletin 1766. The results indicated that control of alligator weed by the. See table 1 in floridas established arthropod weed biological control agents and their targets 20 for a list of arthropod biological control. The biological control of alligatorweed, alternanthera. Alternanthera philoxeroides ufifas center for aquatic. Excluding stock from infested areas, lowering the light levels and nutrient runoff by planting along waterways can help in the ongoing management of alligator weed sites.
Alligator weed is a particularly hard weed to eradicate because it invades both land and water. It is the least known of the alligator weed biological control insects. Alligator weed flea beetle agasicles hygrophila, a biocontrol agent, also contributes to ongoing suppression of aquatic infestations in core areas see. The vast majority of the time, whatever predator is introduced will only control the population of the pest they are meant to target, making it a green alternative to chemical or mechanical control methods. Alligator weed is a restricted invasive plant under the biosecurity act 2014 it must not be given away, sold, or released into the environment without a permit. Control methods biological biological control of alligatorweed has been a phenomenal success, with certain caveats. Biological control three biological control agents from south america have been introduced into new south wales. The biological control of alligatorweed, alternanthera philoxeroides. Julien3 alligator weed alternanthera philoxeroides is an evergreen species native of south america.
Alligator weed can be cut or grazed, but it is difficult to control physically because it will propagate from stem fragments or the roots. The most successful and widely used is agasicles hygrophila commonly called the alligator weed flea beetle. Most considered that further research is needed in tactics for control of the weed. The biological control of alligatorweed, alternanthera philoxeroides, in the unites states of america. Biological control can help manage alligator weed three insects have been released in australia to control alligator weed. Randall and mandy tu biological control biocontrol for short is the use of animals, fungi, or other microbes to feed upon, parasitize or otherwise interfere with a targeted pest species. The alligatorweed flea beetle is widely distributed in the southeastern united states and in many countries where it has been intentionally introduced for biological control. The alligator weed flea beetle and two other biological controls were released in florida, greatly reducing the amount of land covered by the plant. University of georgia center for invasive species and ecosystem health. The plant tends to grow in or near water but can also grow on dry land. Management of aquatic alligator weed alternanthera.
It takes root in shallow water, interfering with navigation, irrigation, and flood control. Biological control plant management in florida waters. It is regarded as one of the worst weeds in australia because of its invasiveness, potential for spread, and economic and environmental impacts. During the past 50 years, eighteen biological controls have been evaluated overseas, studied in quarantine, and released in florida and throughout the southeastern u. Alternanthera philoxeroides is a perennial with prostrate, sprawling, floating hollow stems, often in a dense tangled mass, rooted in shallow water or growing from the shoreline, occasionally freefloating long and lakela 1971. Pathogens as potential classical biological control agents. An innovative method for the biological control of alternanthera philoxeroides yusong cao1, huiming. The alligatorweed flea beetle louisiana state university. Alligator weed alternanthera philoxeroides summary.
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