Management Information
Control strategies must address both watershed management (to reduce nutrient supply) and direct weed control (eg: by introduction of biological control agents) (FAO Undated). Nutrient run-off into infestations should be minimised. Heavy nutrient loadings in water come from erosion of cultivated land, cattle yards, domestic and municipal sewerage outfalls and wastewater discharges from factories. This nutrient inflow can be reduced or prevented by treating water before discharging it into waterways (Burton 2005).
Preventative measures: A Risk assessment of Eichhornia crassipes for Australia and the Pacific was prepared by Pacific Island Ecosystems at Risk (PIER) using the Australian risk assessment system (Pheloung, 1995). The result is a score of 14 and a recommendation of: reject the plant for import (Australia) or species likely to be a pest (Pacific).
Mechanical: Small infestations of E. crassipes can be controlled by pulling (Randall and Rice. Unpub., in Batcher Undated). Specially designed harvesting machines may also be utilised. Permanent drainage of the water body will control E. crassipes (Smith et al. 1984) but may not be appropriate if the area is environmentally valuable.
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Location Specific Management InformationAustralia
As part of a control program, nutrient run-off into infestations should be minimised. Heavy nutrient loadings in water come from erosion of cultivated land, cattle yards, domestic and municipal sewerage outfalls and wastewater discharges from factories. This nutrient inflow can be reduced or prevented by treating water before discharging it into waterways and using conservation farming techniques to divert cattle yard effluent and minimise soil erosion.
Users of agricultural (or veterinary) chemical products must always read the label and any permit before using the product, and must strictly comply with the directions on the label and the conditions of any permit. In NSW, numerous herbicides are registered for the control of water hyacinth. The most commonly used techniques for applying herbicides include: high volume spraying with knapsacks and power sprays, and boomspraying. Spraying an entire heavy infestation can cause water hyacinth to sink and result in pollution from the rotting weed. Large masses of the rotting weed will use all the oxygen in the water, killing fish and wildlife. This problem can be avoided by spraying strips or mechanically removing as much of the weed as possible prior to spraying.
Four insect species have been introduced from South America and released by CSIRO since 1975. There are two weevil species, Neochetina eichhorniae and N. bruchi, and two moth species, Niphograpta albiguttalis (previously Sameodes albiguttalis) and Xubida infusella. The weevil N. eichhorniae has been the most successful, playing a key role in destroying large water hyacinth infestations in tropical and temperate areas of Australia. The adult is black, 5 mm long, and feeds on leaves, making small scars. Eggs are laid in the bulbous leaf stalks and the larvae tunnel through the plant tissue, which is then attacked by bacteria and fungi. This causes the plant to become waterlogged and it can die under heavy attack. The lifecycle of N. eichhorniae takes three months but it is inactive during winter. The other weevil, N. bruchi, is active through the winter, and was first released in 1990 with seeming success. It appears that introducing both weevils is the best option, because of their lifecycles are complementary, but they are much less effective in subtropical and cooler areas. The moth N. albiguttalis is well established in northern NSW and Queensland. Its larvae tunnel into the petioles and buds in the same way as X. infusella, which was first released in 1981. New stocks of the latter were released by CSIRO in Queensland but its success is currently unknown. Both species are very damaging to young plants and luxuriant weed growth but their impact is often temporary and patchy.A biological control programme for Eichhornia crassipes was undertaken simultaneously with programmes for the other aquatic invaders Pistia stratiodes, Salvinia molesta and Hydrilla verticillata, to avoid the increase of other invasive species as one was controlled (Mack and Lonsdale, 2002). Benin
Biological control agents against water hyacinth were released in Benin in 1991 (the weevil Neochetina eichhorniae), 1992 (the weevil Neochetina bruchi), 1993 (the moth Niphograpta albiguttalis) and 1999 (the bug Eccritotarsus catarinensis) (IITA 2000, in Julien 2001). Following its release N. bruchi became successfully established in this country, and provides a sufficient level of control (IITA 2000, in Julien 2001). Following its release N. eichhorniae became successfully established in this country, and provides a sufficient level of control. Following its release N. albiguttalis did not become successfully established in this country.
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). California (United States (USA))
506 hectares of hyacinth covered the Delta in 1981, or 241 of the 1094 kilometers of waterways (Finlayson 1983, in Toft 2000). This was the spark to initiate an extensive biological and chemical control program headed by the California Department of Boating and Waterways (DBW), which actively controls coverage of hyacinth with spraying of the chemical 2,4-D. 202 hectares of hyacinth were treated with 2,4-D in 1983 with an annual budget of $200,000. Although the abundance of hyacinth has drastically decreased in the Delta, control efforts have steadily increased, as 985 hectares of hyacinth were chemically treated during 1998-99 with an annual budget of approximately $1,000,000 (CDBW 1998, Pat Thalken Pers. Comm., in Toft 2000). The weevils Neochetina bruchi and N. eichhorniae and the moth Samaodes albiguttalis were released as biological control agents in 1982 and 1983, without much success (USCOE 1985).
There are several reasons why water hyacinth has taken so long to prosper in the Delta. A likely reason is the increase in stable freshwater flows in the area due to dams and the subsequent reduction of the severity of floods and high flows in the winter (which would flush water hyacinth out of the system). Several biocontrol agents, including the water-hyacinth weevils, Neochetina eichhorniae and N. bruchi, and the water-hyacinth moth, Niphograpta albiguttalis, have been used with varying degrees of success since the 1970s in the southeastern U.S. and in California (Julien and Griffiths 1998, in Batcher Undated). These agents slow rates of growth and make plants more susceptible to other causes of mortality such as frost, herbicides and other pathogens (Simberloff et al. 1997, in Batcher Undated). Neochetina bruchi, water-hyacinth weevil (in Coleoptera) is widely established in Florida, and established but uncommon in Louisiana, Texas and California, where E. crassipes nonetheless remains a troublesome pest. It has been reported to be largely responsible for some declines in California populations of E. crassipes. The organism was introduced from Argentina in 1974 (Julien and Griffiths 1998, in Batcher Undated). China
Manual removal has been employed in most areas in China in the past 10 years. It is estimated that more than 100 million RMB yuan (US$12m) was spent on artificial control of water hyacinth each year but the practice was neither economic nor effective. Mechanical control is used in only a few places and cannot provide long term control. In some areas, herbicides such as Roundup and paraquat were used, but they are prohibited in places where the water is used by people and animals.
In China, biological control activities for water hyacinth were initiated in early 1995, when the Biological Control Institute (BCI) introduced two weevils Neochetina eichhorniae and N. bruchi from the USA and Argentina, respectively. Upon the request of the local government, host range tests for the two weevils were conducted in Kunming, Yunnan Province in 1995. Forty-six plant species from 23 families representing local economic, ornamental, and ecologically important plants (Ding et al. 1998, in Jianqing et al. 2001). were tested. As they had done previously in the USA, Australia, India and other countries, host range tests showed the weevils attacked and completed their life cycles only on water hyacinth and they were safe to other local plant species. After host-specificity tests, the weevils were released in the Wenzhou (1996), Zhejiang (1996) and Fujian (1998) Provinces.
The bug Eccritotarsus catarinensis was introduced into China in the early spring 2000 from the Plant Protection Research Institute (PPRI), South Africa but, for unknown reasons, failed to establish. BCI (Biological Control Institute) plans to re-introduce it. Pathogen surveys started in Fujian and Zhejiang provinces in May 2000. Several promising isolates have been screened.
In order to control the weed rapidly, an integrated control system was developed in 1996 by BCI scientists. Several herbicides, e.g. Roundup (41% IPA salt of glyphosate) and Caoganlin (10% salt of glyphosate), were screened to supplement the activity of the weevils. Bioassay tests showed that Roundup and Caoganlin had almost no adverse effect on the weevils. The tests of integrating Roundup at different concentrations with weevils indicated that herbicides had to be used at a lower concentration than normal, so as to not kill the plants too rapidly and not deprive the insects of food and habitat. The details of those tests were reported in the first IOBC water hyacinth workshop in Zimbabwe in 1998 (Ding et al. 1999, in Jianqing et al. 2001).
Water hyacinth is still a big problem in South China despite great efforts at control over the past 10 years. As more and more attention from central and local governments is paid to improvement of the environment, control of water hyacinth is becoming one of their objectives. Biological control will be increasingly employed but the public and government officials need to be made aware of the importance of biological control. BCI research on biological and integrated control of water hyacinth will focus on the following subjects in the next few years by means of national and international collaborations: (1) Study of the factors influencing the level of control of water hyacinth achieved by weevils, (2) Distribution of the weevils into more areas and introduction of new insects from abroad. An agreement between the South African and Chinese governments has been signed for collaboration on water hyacinth over the next three years. BCI will obtain help from PPRI for the importation of new natural enemies e.g. E. catarinensis, (3) Conduct of field tests of integrated control on a large scale, (4) Survey of pathogens in South China and introduction of promising fungi from abroad. In BCI a pathogen laboratory has been set up for the study of control of the weed by this means. Congo, Republic of the
Biological control agents were released in Congo in 1999 (the weevils Neochetina bruchi and Neochetina eichhorniae) to control water hyacinth (IITA 2000, in Julien 2001). The status of N. bruchi following release in this country is under evaluation (IITA 2000, in Julien 2001). The status of N. eichhorniae following release in this country is under evaluation (IITA 2000, in Julien 2001). Cuba (Greater Antilles)
A biological control agent (the weevil Neochetina bruchi) was released in Cuba in 1995 to control water hyacinth. Following its release N. bruchi became successfully established in this country, however the level of control it provides is unknown. Dianchi Lake (China)
Countries such as Egypt have banned the use of chemicals to control water hyacinth (Navarro 2001).
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Egypt
Biological control agents (the weevils Neochetina bruchi and Neochetina eichhorniae) were released in Egypt in 2000 to control water hyacinth (Fayad et al. 2001, in Julien 2001). The status of N. bruchi following release in this country is under evaluation (Fayad et al. 2001, in Julien 2001). The status of N. eichhorniae following release in this country is under evaluation (Fayad et al. 2001, in Julien 2001). Florida (USA) (United States (USA))
Water hyacinth in Florida is now under maintenance controlhanks to years of concerted effort by local, state and federal water managers. The plants have been kept at a low level using herbicides, machines and biocontrol insects. It is believed that only a year of non-constant vigilance would be needed for water hyacinth to return to heavy infestation levels (which would require millions of dollars worth of investment to reduce to maintenance level again) (University of Florida 1997).
In Florida, the U.S. Army Corps of Engineers attempted mechanical removal in the early 1960’s, but few machines could operate in shallow waters. The herbicide 2,4-D has been applied effectively as a control agent in Florida waters since the 1960’s (Batcher Undated).
Niphograpta albiguttalis (synonym Sameodes albiguttalis), water-hyacinth moth (in Lepidoptera) is established in Florida, Louisiana, and Mississippi. It is reported to have significant impacts on new, developing colonies of water hyacinth but otherwise offers only sporadic and patchy control (Julien and Griffiths 1998, in Batcher Undated). Neochetina bruchi, water-hyacinth weevil (in Coleoptera) is widely established in Florida, and established but uncommon in Louisiana, Texas and California, where E. crassipes nonetheless remains a troublesome pest. It has been reported to be largely responsible for some declines in California populations of E. crassipes. The organism was introduced from Argentina in 1974 (Julien and Griffiths 1998, in Batcher Undated). Fujian (China)
In 1998 biological control agents, the weevils Neochetina eichhorniae and N. bruchi, were distributed to Fuzhou, Fuqing and Fuan cities of Fujian Province where water hyacinth was causing great damage. They established quickly in the Fujian Province, which is warmer than the Zhejiang Province. Significant control has been achieved at several release sites but no detailed survey results are available yet. Ghana
Biological control agents were released in Ghana in 1994 (the weevils Neochetina bruchi and Neochetina eichhorniae) and 1996 (the moth Niphograpta albiguttalis) to control water hyacinth. Following its release N. bruchi became successfully established in this country, however the level of control it provides is unknown. Following its release N. eichhorniae became successfully established in this country, however the level of control it provides is unknown. The status of N. albiguttalis following release in this country is unknown. Guam
Two weevils (Neochetina spp.) and a moth (Sameodes albuguttalis) have been released for biological control, with limited success. Honduras
The mottled water hyacinth weevil (Neochetina eichhorniae) has been been established in Australia, Fiji, Honduras, India, Malaysia, Papua New Guinea, South Africa and Thailand for control of water hyacinth. India
The mottled water hyacinth weevil (Neochetina eichhorniae) has been been established in Australia, Fiji, Honduras, India, Malaysia, Papua New Guinea, South Africa and Thailand for control of water hyacinth. Indonesia
Biological control agents were released in Indonesia in 1979 (the weevil Neochetina eichhorniae) and 1996 (the weevil Neochetina bruchi) to control water hyacinth. Following its release N. bruchi became successfully established in this country, however the level of control it provides is unknown. Following its release N. eichhorniae became successfully established in this country, however, it did not provide a sufficient level of control. Israel
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Jordan
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Kenya
Biological control agents were released in Kenya in 1993 (the weevil Neochetina eichhorniae) and 1995 (the weevil Neochetina bruchi) to control water hyacinth. Following its release N. bruchi became successfully established in this country, and provides a sufficient level of control. Following its release N. eichhorniae became successfully established in this country, and provides a sufficient level of control.
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Lake Seminole (United States (USA))
Extensive herbicide treatment between 1960 and 1962 devastated the water hyacinth population, and another invasive macrophyte, Alternanthera philoxeroides expanded its coverage. This species was subject to a biological control programme in 1968. In the year following its decline, water hyacinth rapidly expanded from occupying a few hectares to 2030 ha. These two species have fluctuated over the past twenty years, each taking up the slack left by the other. Lake Victoria
Three basic techniques exist for its control; mechanical, biological and chemical. Chemical control is least favoured owing to the potential damage that herbicides could cause the lake and surrounding agriculture. Mechanical removal has been attempted but is largely ineffective. This is as a result of the cost of mechanical control, due to expensive machinery and manpower and the fact that water hyacinth grows so quickly. Biological control is therefore the most favoured method of control. In 1995 the Kenya Agricultural Research Institute (KARI) released Neochetina eichhorniae (mottled water hyacinth weevil) a native tropical American bug that feeds exclusively on water hyacinth. A mass rearing programme was also begun which has now released at least 142,000 weevils at 30 sites along the Lake Victoria shoreline (LVEMP 2000, in Williams Undated).
It is believed that water hyacinth has a critical threshold of 5.0 weevils per plant (Mailu 1999, in Williams Undated) and recent weevil populations of 5.4 and 6.1 individuals per plant have been reported at Police Pier and Homa Bay respectively (LVEMP 2000, in Williams Undated). Indeed water hyacinth has now been considerably reduced and succession of the plant bed mats by Hippograss (Vossia cuspidator) and aquatic ferns and sedges such as Cyperus papyrus and Ipomea aquatica have overtaken water hyacinth in many coastal regions of Lake Victoria. The question still remains however as to why water hyacinth disappeared so quickly. The Ninio events of 1998 and '99 may have played a part or a change in nutrient or ideal growth conditions may have occurred. The weevils may have done their job and reached critical levels. No one knows for sure. As a result no one knows if water hyacinth will return or what conditions are required for the resurgence of water hyacinth. Indeed it appears that very few measurements were taken concerning the growth or decline of water hyacinth and environmental variables associated with these growth patterns. Lake Victoria (Kenya) (Kenya)
More recently different countries have grown wary of chemical control because of concerns for potential environmental damage, and have shifted most of their interest to biological control, e.g. Lake Victoria (Navarro 2001). Lake Victoria (Tanzania) (Tanzania, United Republic of)
More recently different countries have grown wary of chemical control because of concerns for potential environmental damage, and have shifted most of their interest to biological control, e.g. Lake Victoria (Navarro 2001). Lake Victoria (Uganda)
More recently different countries have grown wary of chemical control because of concerns for potential environmental damage, and have shifted most of their interest to biological control, e.g. Lake Victoria (Navarro 2001). Lebanon
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Louisiana (United States (USA))
The larval stage of Bellura densa (formerly Arzama densa), a native southern US moth commonly known as pickerelweed borer attacks water hyacinth. Efforts were made in the early 1980s to augment natural populations of the moth's larvae in an effort to reduce water hyacinth infestations in Louisiana. There was little impact (University of Florida 2001).
Niphograpta albiguttalis (synonym Sameodes albiguttalis), water-hyacinth moth (in Lepidoptera) is established in Florida, Louisiana, and Mississippi. It is reported to have significant impacts on new, developing colonies of water hyacinth but otherwise offers only sporadic and patchy control (Julien and Griffiths 1998, in Batcher Undated). Neochetina bruchi, water-hyacinth weevil (in Coleoptera) is widely established in Florida, and established but uncommon in Louisiana, Texas and California, where E. crassipes nonetheless remains a troublesome pest. The organism was introduced from Argentina in 1974 (Julien and Griffiths 1998, in Batcher Undated). Malawi
Water hyacinth appeared in southern Malawi during the late 1960s, and spread slowly northwards in the Lower Shire River, but in 1995 it was found in the Upper Shire River, just south of Lake Malawi. It is now present in most parts of the Shire River, and in a number of other locations, including the far north of the country. Biological control was initiated in 1995 under a UK Department for International Development funded project, and is now being continued through a World Bank-funded project. About 200,000 Neochetina have been reared and released, mainly in the Shire River, but recently at other sites outside the Shire. The beetles are well established in the Shire, though establishment and subsequent population build-up has been faster in the Lower Shire than the Upper and Middle Shire. Water hyacinth infestation in the Shire River is now less than it was two years ago, but it is too early to conclude that this is the result of the biological control campaign. As new infestations appear elsewhere in the country, biological control agents will be released to limit build-up of the weed (Phiri et al. 2001).
Biological control agents were released in Malawi in 1995 (the weevils Neochetina bruch and Neochetina eichhorne) and 1996 (the moth Niphograpta albiguttalis and the bug Eccritotarsus catarinensis) to control water hyacinth. Following its release N. bruchi became successfully established in this country, and the level of control it provides is under evaluation. Following its release N. eichhorniae became successfully established in this country, and the level of control it provides is under evaluation. The status of N. albiguttalis following its release in this country is under evaluation (Julien 2001). Malaysia
The mottled water hyacinth weevil (Neochetina eichhorniae) has been been established in Australia, Fiji, Honduras, India, Malaysia, Papua New Guinea, South Africa and Thailand for control of water hyacinth. Mexico
Biological control agents were released in Mexico in 1972 (the weevil Neochetina eichhorniae) and 1995 (the weevil Neochetina eichhorniae) to control water hyacinth. Following its release N. bruchi became successfully established in this country, and the level of control it provides is under evaluation. Following its release N. eichhorniae became successfully established in this country, however, it did not provide a sufficient level of control. Mexico
In Mexico, monitoring has been done on changes in planktonic and benthic communities in waters flowing into and out of impoundments (the primary target of control) and of herbicidal (2,4-D) residues in water, sediment and tissues of edible fish species (Gutierrez et al. 1996 in ESA 2000). Mississippi (United States (USA))
Niphograpta albiguttalis (synonym Sameodes albiguttalis), water-hyacinth moth (in Lepidoptera) is established in Florida, Louisiana, and Mississippi. It is reported to have significant impacts on new, developing colonies of water hyacinth but otherwise offers only sporadic and patchy control (Julien and Griffiths 1998, in Batcher Undated). Moscow (Russian Federation)
Despite the fact that they can sometimes can form large floating mats during hot summers (even under Moscow climatic conditions), the first frosts in October kill them completely. E. crassipes and Pistia stratiodes can hardly become established in natural systems of the middle European Russia, although they may be potentially hazardous for southern regions of the country. Mozambique
Biological control agents were released in Mozambique in 1972 (the weevils Neochetina bruchi and Neochetina eichhorniae) to control water hyacinth. Following its release N. bruchi became successfully established in this country, however the level of control it provides is unknown. Following its release N. eichhorniae became successfully established in this country, however the level of control it provides is unknown. Myanmar (Burma)
A biological control agent (the weevil Neochetina eichhorniae) was released in Myanmar in 1980 to control water hyacinth. Following its release N. eichhorniae became successfully established in this country, however the level of control it provides is unknown. New South Wales (Australia)
These infestations are now under control but require annual monitoring and maintenance.
The moth N. albiguttalis is well established in northern NSW and Queensland. Its larvae tunnel into the petioles and buds in the same way as X. infusella, which was first released in 1981. New stocks of the latter were released by CSIRO in Queensland but its success is currently unknown. Both species are very damaging to young plants and luxuriant weed growth but their impact is often temporary and patchy. New Zealand
Long term programmes are required to prevent re-infestation of sites. The Ministry of Agriculture and Forestry contracts a monitoring and control programme aimed at eliminating water hyacinth from New Zealand. Nigeria
In Nigeria, fish populations were monitored before and after application of glyphosate. Fish populations increased dramatically after reduction in the extent of the E. crassipes mats following herbicide treatment (Olaleye et al. 1996, in Batcher Undated).Biological control agents were released in Nigeria in 1993 (the weevil Neochetina eichhorniae) and 1995 (the weevil Neochetina bruchi) to control water hyacinth. Following its release N. bruchi became successfully established in this country, however the level of control it provides is unknown. Following its release N. eichhorniae became successfully established in this country, and provides a sufficient level of control.
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Palestinian Territory, Occupied
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Panama
Biological control agents (the weevil Neochetina bruchi and the moth Niphograpta albiguttalis) were released in Panama 1977 to control water hyacinth. The status of N. bruchi following release in this country is unknown. The status of N. albiguttalis following release in this country is unknown. Papua (Irian Jaya) (Indonesia)
WWF-Sahul supported control programmes for Water Hyacinth, Stachytarpheta and Mimosa pigra between 1997-2002 Papua New Guinea
The weevils Neochetina eichhorniae and N. bruchi are available in Papua New Guinea and some areas of Australia. Additional host-specific biological control agents available in the Pacific region include the pyralid moths Niphograpta albiguttalis and Xubida infusellus. Both moths are present in Australia but only X. infusellus is established at one locality in PNG (Julien and Orapa 2001, in Plant Protection Services 2006).
Integrated control of water hyacinth has been attempted in PNG. A weed management programme that integrates physical and biological control methods has been used successfully in a number of places including the Sepik River in PNG, where it is common practice to slash the sides of canals, enabling the current to carry mats of water hyacinth to the sea. However, slashing is not recommended as it promotes spread of the weed to new localities. Philippines
Biological control agents (the weevils Neochetina bruchi and Neochetina eichhorniae) were released in the Philippines in 1992 to control water hyacinth. The status of N. bruchi following release in this country is unknown. The status of N. eichhorniae following release in this country is unknown. Portugal
Early in 1974, a first law (decreto-lei 165/74 de 22 Abril) recognized water-hyacinth (Eichhornia crassipes) as an invasive species, forbidding its importation, culture, selling, transport or possession. Queensland (Australia)
These infestations are now under control but require annual monitoring and maintenance.
The moth N. albiguttalis is well established in northern NSW and Queensland. Its larvae tunnel into the petioles and buds in the same way as X. infusella, which was first released in 1981. New stocks of the latter were released by CSIRO in Queensland but its success is currently unknown. Both species are very damaging to young plants and luxuriant weed growth but their impact is often temporary and patchy. Reunion (La Réunion) 
A research and biocontrol programme against water hyacinth and water lettuce was developed by CIRAD in 2006. The biological control agents selected are two species of weevils Neochetina bruchi and Neochetina eicchorniae (Le Bourgeois, 2006). Rwanda
As part of regional water hyacinth management activities in the Lake Victoria Basin that also involve Kenya, Tanzania, Uganda and several international partners, Rwanda is currently implementing efforts to rear and release the two Neochetina weevil species as biological control agents through coordination of training activities and training visits made to Uganda and Tanzania. Weevils for release in Rwanda have come from stocks maintained in Uganda (Moorhouse Agaba and McNabb 2001).
The implementation of the biological control program within the Kagera River system of Rwanda is expected to further support the long-term control of water hyacinth in the Lake Victoria Basin by reducing water hyacinth biomass in source waters. Funding and technical support for the implementation of the biological control program for water hyacinth in Rwanda are being provided by Clean Lakes, Inc. through a two-year cooperative agreement with the United States Agency for International Development Greater Horn of Africa Initiative through the Regional Lake Victoria Water Hyacinth Management Program (Moorhouse Agaba and McNabb 2001).
Biological control agents (the weevils Neochetina bruci and Neochetina eichhorniae) were released in Rwanda in 2000 to control water hyacinth (Moorhouse et al. 2001). The status of N. bruchi following release in this country is under evaluation (Moorhouse et al. 2001). The status of N. eichhorniae following release in this country is under evaluation (Moorhouse et al. 2001). Solomon Islands
A biological control agent (the weevil Neochetina eichhorniae) was released in the Solomon Islands in 1988 to control water hyacinth. Following its release N. eichhorniae became successfully established in this country, however the level of control it provides is unknown. South Africa
The mottled water hyacinth weevil (Neochetina eichhorniae) has been been established in Australia, Fiji, Honduras, India, Malaysia, Papua New Guinea, South Africa and Thailand for control of water hyacinth. The Argentine water hyacinth moth (Niphograpta albiguttalis or Sameodes albiguttalis) was released and is established in Australia, South Africa and Sudan (University of Florida 2001). It may retard growth in the early stages of water hyacinth mat development. South Australia (Australia)
Infestations in Victoria and South Australia have been eradicated. Sri Lanka
Herbicides and physical removal were too costly to provide lasting solutions. The beetle Neochetina eichhorniae Warner, was introduced in 1988 to attack water hyacinth and stop it from occupying water surfaces which had been cleared of Salvinia molesta, another invasive aquatic plant. This beetle is breeding well but its effectiveness against water hyacinth is unlikely to be evident before 1994.
Adult N. eichhorniae were collected near Brisbane, Australia, and imported into Sri Lanka in February 1988. The original 874 individuals were held in a caged tank for mass rearing at the University of Kelaniya. N. eichhorniae is known to be host-specific to water hyacinth (Harley 1990) and no further host testing was carried out prior to release into the field. Adult progeny were released near Colombo at Peliyagoda and Wellampitya in December 1988 and, in October 1989, 250 adults were collected at Peliyagoda and redistributed: 16 to Eragama, near Ampara in the east of the country; approximately 100 to Udhamuna, east of Hungama in the south; approximately 100 to Alutgama in the southwest. During 1990, further redistributions were made to near Lunuwila and Chilaw in the west. Sudan
Herbicidal control of large infestations of water hyacinth growing under favorable conditions has been attempted only rarely (Scott et al. undated) and even when enormous resources have been invested, as in Sudan, has had little effect.
The Argentine water hyacinth moth (Niphograpta albiguttalis or Sameodes albiguttalis) was released and is established in Australia, South Africa and Sudan (University of Florida 2001). It may retard growth in the early stages of water hyacinth mat development. Syrian Arab Republic
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Taiwan
Biological control agents were released in Taiwan in 1992 (the weevil Neochetina eichhorniae) and 1993 (the weevil Neochetina bruchi) to control water hyacinth. The status of N. bruchi following release in this country is unknown. The status of N. eichhorniae following release in this country is unknown. Tanzania, United Republic of
Biological control agents (the weevils Neochetina bruchi and Neochetina eichhorniae) were released in Tanzania 1995 to control water hyacinth. Following its release N. bruchi became successfully established in this country, and provides a sufficient level of control. Following its release N. eichhorniae became successfully established in this country, and provides a sufficient level of control.
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). Texas (United States (USA))
Neochetina eichhorniae, water-hyacinth weevil (in Coleoptera) is well established throughout the range of E. crassipes in the southeastern U.S. It may be responsible for major reductions in water hyacinth populations in Texas (Batcher Undated). Neochetina bruchi, water-hyacinth weevil (in Coleoptera) is widely established in Florida, and established but uncommon in Louisiana, Texas and California, where E. crassipes nonetheless remains a troublesome pest. The organism was introduced from Argentina in 1974 (Julien and Griffiths 1998, in Batcher Undated). Thailand
The mottled water hyacinth weevil (Neochetina eichhorniae) has been been established in Australia, Fiji, Honduras, India, Malaysia, Papua New Guinea, South Africa and Thailand for control of water hyacinth. Uganda
Biological control agents (the weevils Neochetina bruchi and Neochetina eichhorniae) were released in Uganda in 1993 to control water hyacinth. Following its release N. bruchi became successfully established in this country, and provides a sufficient level of control. Following its release N. eichhorniae became successfully established in this country, and provides a sufficient level of control.
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001). United States (USA)
Several biocontrol agents, including the water-hyacinth weevils, Neochetina eichhorniae and N. bruchi, and the water-hyacinth moth, Niphograpta albiguttalis, have been used with varying degrees of success since the 1970s in the southeastern U.S. and in California (Julien and Griffiths 1998, in Batcher Undated). These agents slow rates of growth and make plants more susceptible to other causes of mortality such as frost, herbicides and other pathogens (Simberloff et al. 1997, in Batcher Undated). Neochetina eichhorniae, water-hyacinth weevil (in Coleoptera) is well established throughout the range of E. crassipes in the southeastern U.S. It may be responsible for major reductions in water hyacinth populations in Texas. It has been reported that herbicides commonly used on E. crassipes have negatively impacted weevil populations. The organism was introduced from Argentina in 1972 (Julien and Griffiths 1998, in Batcher Undated). The fungus Cercospora rodmanii, which is native and widespread in the southeastern U.S., provides generally low levels of control. When present in epidemic proportions, however, it may provide high levels of control. The organism has undergone testing for commercial development (Julien and Griffiths 1998, in Batcher Undated). Vanuatu
Vanuatu has initiated the first stages of their first-ever national biological control of weeds programme against the troublesome pasture weeds Sida acuta, S. rhombifolia and the aquatic weed Eichhornia crassipes with the help of SPC PPS under the EU-PPP Project.
SPC Weeds Officer Mr Warea Orapa delivered 1000 adults of the Sida leaf feeding beetle Calligrapha pantherina (Coleoptera: Chrysomelidae) and 1100 adult weevils of the water hyacinth weevil Neochetina eichhorniae (Coleoptera: Curculionidae) to Vanuatu during the period 19-20 August 2004. These two biological control agents were reared under laboratory conditions at Koronivia Research Station and SPC Nabua in Fiji. They were introduced under Vanuatu Import Permits No. 1000 and 1201. The agents will be reared through to first generation as required under international protocols for the movement of biological control agents in the newly built post-entry quarantine (PEQ) facility at Tagabe, also funded by EU-PPP funds. The activities will be undertaken by Vanuatu Quarantine Plant Protection Officers. Field releases are expected in October 2004 and the agents and weeds will be monitored over a period of 1-2 years (Pacific Pest Info No. 51, August 2004). Victoria (Australia)
Infestations in Victoria and South Australia have been eradicated. Viet Nam (Vietnam)
Biological control agents were released in Vietnam in 1984 (the weevil Neochetina eichhorniae) and 1996 (the weevil Neochetina bruchi) to control water hyacinth. Following its release N. bruchi became successfully established in this country, however the level of control it provides is unknown. The status of N. eichhorniae following release in this country is unknown. Wenzhou (China)
After host-specificity tests, weevils (Neochetina eichhorniae and N. bruchi) were first released at four rivers in Wenzhou and Zhejiang provinces in September 1996. Some 1000 individuals of a mixture of the two weevil species were released at each river. The weevils established at all the four rivers within one year of release. At Lincun River, about 50% of water hyacinth plants were killed in late spring 1998, while a native grass, Paspalum spp., recovered and occupied the space where water hyacinth grew. Since then, the density of water hyacinth has varied seasonally between 10 and 50% of coverage of the water surface. By means of water flow, the weevils spread rapidly to water bodies up to 40 km from the release site by the summer of 2000 (Ding et al., Unpub. Data). Zambia
Biological control agents were released in Zambia in 1971 (the weevil Neochetina eichhorniae, the moth Niphograpta albiguttalis and the mite Orthogalumna terebrantis), 1996 (the weevil Neochetina eichhorniae) and 1997 (the weevil Neochetina bruchi, N. albiguttalis and the bug Eccritotarsus catarinensis) to control water hyacinth (M. Hill Pers. Comm. 2000, in Julien 2001). The status of N. bruchi following release in this country is unknown (M. Hill Pers. Comm. 2000, in Julien 2001). Following its second (1996) release N. eichhorniae became successfully established in this country, however the level of control it provides is unknown. The status of N. albiguttalis following its second (1997) release in this country is unknown (it failed to establish following its 1971 release). Zhejiang (China)
After host-specificity tests, weevils (Neochetina eichhorniae and N. bruchi) were first released at four rivers in Wenzhou and Zhejiang provinces in September 1996 in an attempt to control the weed using biological control. Some 1000 individuals of a mixture of the two weevil species were released at each river. The weevils established at all the four rivers within one year of release. At Lincun River, about 50% of water hyacinth plants were killed in late spring 1998, while a native grass, Paspalum spp., recovered and occupied the space where water hyacinth grew. Since then, the density of water hyacinth has varied seasonally between 10 and 50% of coverage of the water surface. By means of water flow, the weevils spread rapidly to water bodies up to 40 km from the release site by the summer of 2000 (Ding et al., Unpub. Data).
In the early summer of 2000, a colony of the weevils (Neochetina eichhorniae and N. bruchi) was introduced to Ningbo, another city of Zhejiang Province, where they were released in one river. There is some concern about the ability of the weevils to overwinter there. Located at around 30°N, Ningbo is in the north of Wenzhou and Fujian. In some years when it is very cold in winter, the water hyacinth plants die. In the next year, plants may regrow from seed. Hence, tests have been planned to see if the weevils can overwinter in Ningbo.
In 2001 the weevils will be introduced to Guandong Province which is one of the areas in China most seriously affected by water hyacinth damage. Zimbabwe
Biological control agents were released in Zimbabwe 1971 (the weevil Neochetina eichhorniae), 1994 (the moth Niphograpta albiguttalis), 1996 (the weevil Neochetina bruchi) and 1999 (the bug Eccritotarsus catarinensis) to control water hyacinth (G. Chikwenhere Pers. Comm. 2000, in Julien 2001). Following its release N. bruchi became successfully established in this country, and provides a sufficient level of control. Following its release N. eichhorniae became successfully established in this country, and provides a sufficient level of control. The status of N. albiguttalis following release in this country is unknown.
The Water Hyacinth Information Partnership (WHIP) has been conceptualised as an information–communication mechanism to alert communities and decision-makers concerned with water bodies of Africa and the Middle East that are facing impending infestations of water hyacinth. This includes Egypt, Lebanon, Syria, Jordan, Palestine and Israel. It would also foster and facilitate quick reaction to the threat by providing countries with timely information. The vision is that of a region that is able to halt and revert the spread of water hyacinth across its water bodies, preventing water hyacinth from reaching costly crisis levels. WHIP’s mission is, through the use of modern and more traditional information–communication technologies, to target and tap key sources of information and expertise on water hyacinth, to mobilise decision makers and to stimulate efforts to control the weed. In the longer term, the expectation is that WHIP would foster and support the integrated management of water bodies and their basins to diminish soil erosion and other sources of water pollution that favour the growth of aquatic weeds (Navarro 2001).
Management Resources/Links
1. Batcher, Michael S. (no date) Element Stewardship Abstract for Eichhornia crassipes (Martius) Solms. The Nature Conservancy, Virginia, USA.
Summary: Contains names, description, diagnostic characteristics, pest weed status, references and a stewardship summary that includes information on habitat, ecology, biology, impacts, management, monitoring, research. 4. Champion, P.D.; Clayton, J.S. 2001. Border control for potential aquatic weeds. Stage 2. Weed risk assessment. Science for Conservation 185. 30 p.
Summary: This report is the second stage in the development of a Border Control Programme for aquatic plants that have the potential to become ecological weeds in New Zealand. Importers and traders in aquatic plants were surveyed to identify the plant species known or likely to be present in New Zealand. The Aquatic Plant Weed Risk Assessment Model was used to help assess the level of risk posed by these species. The report presents evidence of the various entry pathways and considers the impact that new invasive aquatic weed species may have on vulnerable native aquatic species and communities.
Available from: http://www.doc.govt.nz/upload/documents/science-and-technical/SFC185.pdf [Accessed 13 June 2007] 5. Fact sheet from the Department of Natural Resources, Queensland, Australia. (PDF format) 8. Gee II, David E., pers. comm. 2006. Wildlife Biologist, Guam Division of Aquatic & Wildlife Resources and Guam team member of the Pacific Invasives Learning Network (PILN). 12. Julien, M. H. (ed.) 1992. Biological control of weeds: A world catalogue of agents and their target weeds (3rd edition). CAB International, Wallingford, UK. pp. 77-82, 126, 135-136. 14. Kueffer, C. and Mauremootoo, J., 2004. Case Studies on the Status of Invasive Woody Plant Species in the Western Indian Ocean. 3. Mauritius (Islands of Mauritius and Rodrigues). Forest Health & Biosecurity Working Papers FBS/4-3E. Forestry Department, Food and Agriculture Organization of the United Nations, Rome, Italy. 15. Le Bourgeois, T. 2006. Dossier technique concernant Neochetina eicchorniae et N. bruchi (Coleoptera-Curculionidae) et Neohydronomus affinis (Coleoptera-Curculionidae) pour une demande d'importation et de lâcher à la Réunion en vue de la lutte biologique contre Eichhornia crassipes (Pontederiaceae) et Pistia stratiotes( Araceae), plantes aquatiques exotiques envahissantes des étendues d'eau douce littorales. CIRAD/UMR PVBMT. 35p
Summary: Rapport technique présentant les enjeux de la lutte biologique contre la Jacinthe d'eau et la Laitue d'eau à la Réunion et les différentes étapes du programme. 17. May, Michael, Cristina Grosso, and Josh Collins., 2003. Water hyacinth. Practical Guidebook for the Identification and Control of Invasive Aquatic and Wetland Plants in the San Francisco Bay-Delta Region San Francisco Estuary Institute Oakland, California
Summary: Information on description, economic importance, distribution, habitat, history, growth, and impacts and management of species.
Available from:
http://www.sfei.org/nis/hyacinth.html [Accessed 22 June 2005].
The Guidebook is available from: http://www.sfei.org/nis/ 19. National Pest Plant Accord, 2001. Biosecurity New Zealand.
Summary: The National Pest Plant Accord is a cooperative agreement between regional councils and government departments with biosecurity responsibilities. Under the accord, regional councils will undertake surveillance to prevent the commercial sale and/or distribution of an agreed list of pest plants.
Available from: http://www.biosecurity.govt.nz/pests-diseases/plants/accord.htm [Accessed 11 August 2005] 21. Pacific Pest Info Newsletter. Published by the Secretariat of the Pacific Community: Plant Protection Service, Private Mail Bag, Suva, Fiji Islands. Tel: (679) 3370-733; Fax: (679) 3370-021. 23. Phiri, P.M., Day, R.K., Chimatiro, S., Hill, M.P., Cock, M.J.W., Hill, M.G. and Nyando, E. Progress with Biological Control of Water Hyacinth in Malawi. In: M.H. Julien, M.P. Hill, T.D. Center and Ding Jianquig (eds.). Biological and Integrated Control of Water Hyacinth Eichhornia crassipes (Proceedings PR102 2001)
Summary: Available from: http://www.aciar.gov.au/web.nsf/doc/JFRN-5J4725 [Accessed 27 April 2006] 24. Photos and additional information at University of Florida, Center for Aquatic and Invasive Plants. 25. Raulerson, Dr. Lynn,. pers. comm. 2006. University of Guam (Biology). From information collected by David E. Gee II, Wildlife Biologist. Guam Division of Aquatic & Wildlife Resources and Guam team member of the Pacific Invasives Learning Network (PILN). 26. Room, P.M. and Fernando, I.V.S. 1992. Weed Invasions Countered by Biological Control: Salvinia molesta and Eichhornia crassipes in Sri Lanka, Aquatic Botany 42: 99 - 107.
Summary: This paper gives an excellent outline of the biological control of S. molesta in Sri Lanka between 1982 and 1990, including a history of the weed in the country, an overview of the release and distribution of the weevil (Cyrtobagous salviniae) and an summary of the results and most interesting findings. Also mentions the performance of Neochetina eichhorniae as a biological control agent for water hyacinth (Eichhornia crassipes). 31. The Nature Conservancy photos and Stewardship Abstract. 33. Waterhouse, D. F. 1994. Biological control of weeds: Southeast Asian prospects. Australian Centre for International Agricultural Research, Canberra. p. 68-83. 34. Waterhouse, D. F. and K. R. Norris. 1987. Biological control: Pacific prospects. Inkata Press, Melbourne. p. 332-341. 36. Wilson, Colin, Wildlife Management Officer, Department of Infrastructure, Planning and Environment, Parks & Wildlife Service, Northern Territory, Australia.
Summary: Compilor of original GISD profile of Chromoleana odorata. Results Page: 1
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