General News
Total Page：16
File Type：pdf, Size：1020Kb
News 1N General News Sorting Salvinia Salvinia: USA Begins populations of 'Australian' C. salviniae, Round Two collected originally from Brazil and used in An aquatic fern native to southern Brazil, successful biological control programmes giant salvinia (Salvinia molesta) is consid- Cyrtobagous salviniae was released for the in Australia, Papua New Guinea, South ered one of the most invasive plants in the second time against giant salvinia (Salvinia Africa, and other countries. molesta) in Texas and Louisiana in October world. Its rapid rate of spread is facilitated However, the release permit for the 2001. Weevils for this release were by environmental adaptability coupled with 'Florida' C. salviniae was not extended to obtained from cooperators in Australia an ability to propagate vegetatively from cover the 'Australia' C. salviniae. where they have been used successfully to plant fragments. Regulatory officials in the USDA-APHIS control Salvinia molesta. Following the (Animal Plant Health Inspection Service) second release in the USA, numerous It has been the target of classical biological required that a new permit be issued, which adults and significant damage were found control programmes since the 1960s in involved a lengthy process made more at most of the sites 2 months later in Africa, Asia, and Australia. However, the lengthy when a petition written by another December. The winter season is expected first attempts were unsuccessful in Africa, lab was rejected because of substandard to inhibit any further activity by the weevils India, Fiji, and Sri Lanka because of the research and reporting, thereby causing but we hope to learn if they can overwinter misidentification of the plant as Salvinia further delays in obtaining a general release at locations in east Texas and western auriculata. Researchers surveyed S. auric- permit. In cooperation with Wendy Forno Louisiana. Additional releases of C. ulata in Guyana and Trinidad and found a of Australia (formerly of the Common- salviniae will be conducted if necessary small weevil identified as Cyrtobagous wealth Scientific Industrial Research during the spring and summer of 2002. singularis. Although C. singularis did Organisation, CSIRO) and Sharon establish in several areas, it had no effect on Salvinia molesta has been established in the Docherty and Martin Hill from South the infestations. Salvinia molesta was wild in the USA since at least 1998, but it is Africa (formerly of the Plant Protection separated from S. auriculata in 1972 and its possible that it has been living free in the Research Institute, PPRI), we wrote a new native range in Brazil was discovered in USA for rather longer, as it has been widely petition, which was approved and the 1978. In 1980, what was thought to be a distributed as an ornamental plant and is permit was finally issued, thus facilitating biotype of C. singularis from S. molesta easily obtained via the Internet. First the second releases. was introduced at Lake Moondarra in discovered in eastern Texas, it now extends Studies designed to sort out the differences Australia and proceeded to destroy more into western Louisiana. between the populations of C. salviniae are than 30,000 t of S. molesta in less than one continuing. Preliminary data shows that year. Closer examination of the 'biotype' The first release of C. salviniae was 'Florida' weevils are equally attracted to resulted in its elevation to species status, conducted in June 1999 using weevils both S. molesta and S. minima,canrepro- namely C. salviniae.Thisnewspecies collected from common salvinia, S. duce on S. molesta, and live longer and lay reversed earlier failures and successful minima, in Florida rather than the tried- more eggs on S. molesta than on S. minima. programmes were conducted in Australia, and-tested stock from Australia, as this In addition, the 'Australia' weevil has Fiji, Ghana, Kenya, Malaysia, Papua New obviated the risk of introducing new demonstrated the ability to suppress S. Guinea, South Africa, Zambia, Zimbabwe, pathogens or parasites into the USA. minima in tank studies. India, Botswana, Namibia, and Sri Lanka, Cyrtobagous salviniae had been introduced where control has been dramatic and rapid: accidentally into Florida prior to 1960 and By:P.W.TippingandT.D.Center in many cases S. molesta was reduced by is now found throughout the state feeding USDA-ARS Invasive Plant Laboratory, on S. minima, and has also been found more than 90% in less than a year following 3205 College Ave., Fort Lauderdale, FL attacking S. molesta at one site in release of C. salviniae*. 33314, USA southwestern Florida. Unfortunately, the Email: [email protected] / results of the first biocontrol attempt were Here we look at progress in two [email protected] unclear as many of the original Texas and programmes to combat recent invasions. Fax: +1 954 476 9169 Louisiana release sites were corrupted or The first, in the USA, underlines how taxo- destroyed by floods, droughts, saltwater nomic uncertainties and confusion can still intrusion, or landowner actions. Significant confound biocontrol. The second, in the damage of the salvinia was noted at one Salvinia: West Africa Senegal River in Senegal and Mauritania, release site, though, before it was destroyed Battles Invasives deals with management of invasive species by the landowner (despite a previous to mitigate threats to both the environment agreement not to do so). The freshwater wetland systems of and economic development. Mauritania and Senegal are crucial habitats Gene sequence studies in early 2000 found for Palaearctic migrant birds crossing 200 *Tipping, P. (2000) Biological control minor differences between 'Australia' and km of the arid western Sahara Desert, and programmes for giant salvinia: history and 'Florida' weevils in the number of base pairs as such they are the focus of national and update on US efforts. Water Hyacinth News in the D2 gene. Further releases of the international conservation efforts. A series No.2,p.6. 'Florida' weevils were suspended because of national parks has been set up by the of the taxonomic uncertainty this created, governments of Senegal and Mauritania in and instead efforts were redirected to recognition of the importance of the Are we on your mailing list? BiocontrolNews and Information is always pleased to receive news of research, conferences, new products or patents, changes in personnel, collaborative agreements or any other information of interest to other readers. If your organization sends out press releases or newsletters, please let us have a copy. In addition, the editors welcome proposals for review topics. 2N BiocontrolNews and Information 2002 Vol. 23 No. 1 ecosystems, many of which are designated tation, and notably dense stands of Typha cultivation. OMVS constructed four sluices World Heritage Sites and/or recognized as australis (reed mace) in shallow water, and to re-flood the area and restore the pre-dam Wetlands of International Importance by mats of floating weeds, initially Pistia hydrological scheme and to preserve the Ramsar. The wetlands and the rivers that stratoites (water lettuce) and now Salvinia. rich biodiversity. Since then IUCN (World feed them, though, are also fundamental to Besides visible impacts on the riparian Conservation Union) has built two more maintaining local livelihoods and regional human and wildlife populations there have dykes and sluices to optimize water economies, providing fishing, irrigation for been less-evident effects, including a management, and sponsored artificial agriculture and potable water supplies for substantial increase in malaria, for flooding by the park management. In both rural and urban areas. Traditionally example, owing to an increase in year- consequence, 16,000 ha of salt desert are maintained by varying seasonal rainfall, round standing water for breeding. Down- restored and the ecosystem is reviving, a advances in hydrology now create oppor- stream, in contrast, conditions became unique example of the reconstruction of a tunities for water flow to be regulated to more saline and water supply virtually natural environment. Diawling was made a meet needs throughout the year. Such ceased during the dry season. These National Park in 1991 with a mandate to changes inevitably lead to disruption of the changes were enhanced by embankments integrate conservation and development ecosystem, and restoring a balance that is built to separate the river from the (including fishing and pastoralism within sustainable in the long term is proving a floodplain, which led to large parts of the its boundaries), and was designated a challenge, and is having to overcome some floodplain and estuary becoming drier. Ramsar site in 1994. It, too, has been unexpected obstacles including invasion by invaded by Typha, and more recently by The emergence of an invasive weed threat alien water weeds, with Salvinia molesta Salvinia. is thus part of a wider issue: the impact of (giant salvinia) causing alarm most changing land-use patterns and hydro- Waves of Invasives recently. Concerted efforts involving local, logical management on the natural national, regional and international co- The invasive weed problem surfaced in the ecosystems along the lower Senegal river, operation have been made to mitigate the Djoudj Park soon after the Diama Dam where salinity traditionally varied from Salvinia threat. Mechanical clearance became operational in 1988. Reports of nearly fresh (during inundation) to brackish provided