Water Hyacinth (Eichhornia crassipes)

The abstracts presented here give an illustration of the variety of biocontrol agents that have been investigated for the control of the water hyacinth (Eichhornia crassipes) in recent years. They include use of Neochetina species and various fungal pathogens, which have been investigated for the biological or integrated control of this prolific weed.

CABI BIOSCIENCE has an on-going project with the Fisheries Department to control the weed in Malawi. It has four components:

Biological control

Two species of weevil (Neochetina species) and a mite (Orthogallumna terebrantis) have been established on the weed and are now widely distributed. Two further species - a bug, Eccritotarsus catarinensis, and a moth Sameodes albigutalis, have also been released but establishment of these has not yet been confirmed.

Socio-economic studies

These have quantified the effect of the weed on riparian communities and provided baseline data against which to measure any future reduction in the weed’s status as a result of biological control

Community participation

Fishing communities are being informed of the need to prevent further spread of the weed, mechanisms for its containment, and especially about its biological control. This knowledge will help them to assist in the effective distribution of biological control agents throughout the range of the weed, and to understand more about the weed, its impact and options for its control

Biodiversity studies

Methods of monitoring the impact of the weed on biodiversity are being developed so that the effects of the weed on wetland ecology can be better determined, and in subsequent years, the ameliorating effects of control options quantified.

CABI BIOSCIENCE has developed a proposal for a project to investigate the development of a bioherbicide based upon fungi pathogenic to water hyacinth, involving expertise in water hyacinth pathology from Egypt, South Africa and Zimbabwe, together with expertise on biopesticide formulation and production from CABI BIOSCIENCE.

For further information on the work of CABI BIOSCIENCE relating to the control of the water hyacinth, please contact .

Water hyacinth is included in the Crop Protection Compendium Module 1, for which more information on the 1998 Edition is available.

Related items included in PEST CABWeb^®:

• Weed Abstracts
• Biocontrol News and Information
• Review of Plant Pathology
• Review of Agricultural Entomology

Information is also available on:

• Crop Protection Compendium Module 1

TI: Water hyacinth in Zambia: restoring the balance on the Kafue River.
AU: Hill, M.
JN: Plant Protection News
YR: 1997
NO: No. 47
PP: 11-13
LA: En
AA: Weeds Research Division, Rietondale, Private Bag X134, Pretoria 0001, South Africa.
AB: The weed status of Eichhornia crassipes on the Kafue River in Zambia is described, and previous and current attempts to implement biological control measures are discussed. Neochetina eichhorniae, Orthogalumna terrebrantis O. terebrantis and Sameodes albiguttalis were released in the 1970s; 2 species failed to establish but O. terrebrantis established extensively. Since the late 1980s there has been a massive increase in E. crassipes populations, attributed to the impact of dam construction, increased eutrophication and low rainfall, and this has led to permanent mats and blockages being formed. Since 1993, N. eichhorniae and S. albiguttalis have been rereleased and the former is established. Eccritotarsus catarinensis has also been released, and releases of N. bruchi are planned. It is argued that this suite of introduced agents together with the pathogen Acremonium zonatum which occurs in high numbers on the weed should reduce the vigour and reproductive potential of the plant.
DE: weeds \ aquatic weeds \ Eichhornia crassipes \ rivers \ biological control \ weed control \ Neochetina eichhorniae \ Orthogalumna terebrantis \ Acari \ Sameodes albiguttalis \ plant pests \ insect pests \ biological control agents \ eutrophication \ Eccritotarsus catarinensis \ Miridae \ Neochetina bruchi \ plant pathogens \ plant diseases \ plant pathogenic fungi \ Acremonium zonatum \ Acremonium
GL: Zambia
AN: 0W04702065 \ 0E08605932

TI: The water hyacinth (Eichhornia crassipes) problem in West Africa and proposals for control strategies.
CT: Seizième conférence du COLUMA. Journés internationales sur la lutte contre les mauvaises herbes, Reims, France, 6-8 décembre 1995. Tome 3.
AU: Pieterse, A. H. \ Mangane, A. \ Traoré, M. \ Klashorst, G. van de \ Rijn, P. J. van
YR: 1996
PP: 1393-1400
BN: ISBN 2-905550-67-8 (vol. 3) \ ISBN 2-905550-64-3 (set)
LA: En
LS: fr
MS: 7 ref.
AA: Royal Tropical Institute, Department of Agriculture and Enterprise Development, Mauritskade 63, 1092 AD Amsterdam, Netherlands.
AB: The spread, current weed status and control methods for Eichhornia crassipes are reviewed in the context of the African Development Bank ­ ECOWAS (Economic Community of West African States) project which began in 1992. The spread of E. crassipes in West Africa following its arrival in 1977 in Benin is described. Ongoing control programmes and projects in countries now affected are also described. Nigeria initially used manual clearance but mechanical harvesters have been introduced; chemical and biological control options have both been considered and Neochetina eichhorniae has been released. Manual control is practised in Benin but a biocontrol programme is in progress and N. eichhorniaeand N. bruchi have been released. Ghana implemented a chemical control programme which eradicated the weed on lagoons but it remains in small waterways and a biocontrol programme has been initiated; Neochetina spp. have been released and other species will be used also. In Côte d'Ivoire barriers were used to contain the weed, but a biological control project is planned. In Niger a manual clearance programme has been used. Local and industrial initiatives have operated in Mali. Proposed follow-up projects within the framework of ECOWAS are outlined, and these focus on the implementation of biological control measures using insect natural enemies and physical control by mechanical harvesting. The need for public awareness is also addressed.
DE: conferences \ weeds \ aquatic weeds \ Eichhornia crassipes \ spread \ weed control \ physical control \ manual weed control \ mechanization \ chemical
control \ biological control \ biological control agents \ Neochetina eichhorniae \ Neochetina bruchi \ lagoons \ waterways \ natural enemies
GL: West Africa \ Benin \ Ghana \ Cote d'Ivoire \ Niger \ Mali
AN: 0W04701653

TI: Experimental evaluation of Alternaria eichhorniae as a biocontrol agent of waterhyacinth.
CT: Proceedings of the second international weed control congress, Copenhagen, Denmark, 25-28 June 1996: Volumes 1-4 [edited by Brown, H.; Cussans,
G. W.; Devine, M. D.; Duke, S. O.; Fernandez-Quintanilla, C.; Helweg, A.; Labrada, R. E.; Landes, M.; Kudsk, P.; Streibig, J. C.].
AU: Aneja, K. R.
YR: 1996
PP: 1325-1330
BN: ISBN 87-984996-1-0
LA: En
MS: 15 ref.
AA: Department of Botany, Kurukshetra University, Kurukshetra 132 119, India.
AB: Studies were carried out during 1987-93 in the states of Haryana, Indian Punjab and Delhi, India, to investigate the control of water hyacinth (Eichhornia crassipes) with the fungal pathogen Alternaria eichhorniae, and to evaluate the effects of temperature (5-40°C) on fungal development. The pathogenicity of the isolate to E. crassipes was proved on detached leaves and whole plants. The growth rate of A. eichhorniae was maximum on E. crassipes dextrose agar, followed by potato dextrose agar, nutrient agar, and martin agar. The best sporulation was found at 25°C, while no sporulation was observed at 5°C and 45°C. However, some mycelial growth was observed at 5°C. In vitro, the most rapid disease development was at 25°C, with slower development at 15°C and 35°C. In outdoor experimental tanks, the first spots appeared 7 days after spraying with a conidial suspension. In covered tanks, the entire surface of leaf laminae was covered within 20 days after inoculation and the falling of laminae started after 24 days. The amount of leaf infection in covered tanks was greater than in uncovered tanks. Complete mortality or sinking of the laminae was observed after 2 months.
DE: conferences \ international weed control congress \ aquatic weeds \ weed control \ biological control \ plant pathogenic fungi \ inoculation \ Eichhornia crassipes \ Alternaria eichhorniae \ growth \ temperature
GL: India \ Delhi \ Haryana \ Indian Punjab
AN: 0W04701246

TI: Identification of indigenous fungi for biocontrol of waterhyacinth in Mexico.
CT: Proceedings of the second international weed control congress, Copenhagen, Denmark, 25-28 June 1996: Volumes 1-4 [edited by Brown, H.; Cussans, G. W.; Devine, M. D.; Duke, S. O.; Fernandez-Quintanilla, C.; Helweg, A.; Labrada, R. E.; Landes, M.; Kudsk, P.; Streibig, J. C.].
AU: Martinez Jimenez, M.
YR: 1996
PP: 1301-1305
BN: ISBN 87-984996-1-0
LA: En
MS: 9 ref.
AA: Impacto Ambiental, Area de Malezas Acuáticas, Instituto Mexicano de Tecnología del Agua, Paseo Cuauhnáhuac 8532, Jiutepec, Morelos, Mexico.
AB: A study was carried out during the rainy season of 1993 in southern and central Mexico to identify indigenous fungal pathogens of water hyacinth (Eichhornia crassipes). Plants with symptoms of diseases were collected and screened for fungi. Cercospora spp. and Acremonium zonatum were identified as potential mycoherbicides. Inoculation of these fungi on healthy E. crassipes produced the same disease symptoms as observed in the field.
DE: conferences \ international weed control congress \ aquatic weeds \ weed control \ biological control \ plant pathogenic fungi \ Cercospora \ Acremonium zonatum \ Eichhornia crassipes
GL: Mexico
AN: 0W04701245

TI: Beating the dam busters.
AU: Watts, R.
JN: African Farming and Food Processing
YR: 1997
NO: No. March/April
PP: 25-26
LA: En
AB: Two of the main threats to old dams in Africa are silting and weed infestation by the water hyacinth [Eichhornia crassipes]. The problems facing existing dams and the measures used to protect them are discussed in this report, based upon findings from Lake Chivero in Zimbabwe.
DE: dams \ geological sedimentation \ weed control \ Eichhornia crassipes \ aquatic weeds
GL: Zimbabwe
AN: 0W04701247 \ 0S06103424

TI: Effects of 3 herbicides on mortality of eggs, larvae, pupae and adults of water hyacinth weevil, Neochetina eichhorniae Warner (Col.: Curculionidae).
AU: Ding JianQing \ Wang Ren \ Wang NianYing \ Fu WeiDong \ Chen ZhiQun
JN: Chinese Journal of Biological Control
YR: 1998
VL: 14
NO: 1
PP: 7-10
LA: Ch
LS: en
MS: 9 ref.
AA: Institute of Biological Control, CAAS, Beijing 100081, China.
AB: The effects of 3 herbicides, glyphosate, paraquat and Londex [Londax = bensulfuron] at recommended rates on the mortality of the water hyacinth weevil, Neochetina eichhorniae, were tested in both laboratory and field. The hatching rates of the eggs in direct contact with glyphosate, paraquat, bensulfuron and water (control) were 83.3%, 93.3%, 92.2% and 95.6%, respectively. When these herbicides were sprayed on the water hyacinth leaves infested with weevil eggs, the hatching rates were 90.0%, 53.4%, 85.6% and 93.6%, respectively. There were no significant effects on the mortality of the first-instar larvae and pupae of the weevil treated with the herbicides. The eggs oviposited by each female per day treated with glyphosate, paraquat, bensulfuron were 1.14, 0.17, 0.27, respectively and the control was 1.13. The survival rate of the adults fed on leaves sprayed with the 3 herbicides and water were 92.5%, 0, 95.0% and 97.5% after 70 d, respectively. The order of the effect of the 3 herbicides on the weevil was paraquat

TI: Role of macronutrients in feeding of Neochetina spp. (Coleoptera: Curculionidae) and their water hyacinth killing efficiency.
AU: Mishra, A. K. \ Shrivastava, S. K.
JN: Indian Journal of Environment and Toxicology
YR: 1997
VL: 7
NO: 2
PP: 108-109
LA: En
MS: 1 ref.
AA: Central Integrated Pest Management Centre, Raipur 492 001, M.P., India.
AB: Studies were conducted under ambient conditions to determine the effect of macronutrients (N, P, K, S, Mg and Ca) at various concentrations (1, 10, 25 and 50 p.p.m.) on the feeding rate of Neochetina bruchi and N. eichhorniae on water hyacinth, Eichhornia crassipes. All the nutrients had a positive effect on the feeding rate at all the concentrations. With N supplementation a maximum feeding rate of 19.8 ± 0.32 to 65.9 ± 0.41 and 23.1 ± 0.32 to 57 ± 0.20 cm³ was recorded for Neochetina bruchi and N. eichhorniae, respectively, and for weed killing a minimum period was required (34.0 ± 0.89 to 29.3 ± 1.03 and 30.5 ± 0.83 to 26.8 ± 0.75 days). With an increase in the concentration of calcium the feeding rate decreased (15.1 ± 0.37 to 1.7 ± 0.11 and 15.3 ± 0.35 to 1.4 ± 0.27 cm³), and a longer period of feeding was required (53.5 ± 0.54 to 58.3 ± 0.51 and 45.1 ± 0.4 and 54.3 ± 0.51 days) by N. bruchi and N. eichhorniae, respectively, to kill E. crassipes.
DE: Neochetina bruchi \ Neochetina eichhorniae \ Eichhornia crassipes \ nutrients \ aquatic weeds \ natural enemies \ food plants \ biological control agents \ feeding behaviour \ biological control
AN: 0W04702498 \ 7E01901059

TI: Optimum population of Neochetina eichhorniae required for the suppression of Eichhorniae crassipes.
AU: Kumar, K. M. S. \ Joseph, D.
JN: Indian Journal of Entomology
YR: 1996
VL: 58
NO: 2
PP: 143-148
LA: En
MS: 6 ref.
AA: AICRP on Biological Control of Crop Pests and Weeds, College of Horticulture, Trichur, Kerala, India.
AB: A replicated field experiment was conducted in India during 1987-89 to determine the optimum population size of Neochetina eichhorniae required for the suppression of the aquatic weed, Eichhornia crassipes. The root length, petiole length and lamina width of plants were adversely affected by infestation. Infested floating plants took longer to collapse than rooted plants.
DE: natural enemies \ beneficial insects \ Neochetina eichhorniae \ Eichhornia crassipes \ aquatic weeds \ biological control agents \ biological control
GL: India

TI: Water hyacinth: a tropical worldwide problem and methods for its control.
CT: Proceedings of the second international weed control congress, Copenhagen, Denmark, 25-28 June 1996: Volumes 1-4 [edited by Brown, H.; Cussans,
G. W.; Devine, M. D.; Duke, S. O.; Fernandez-Quintanilla, C.; Helweg, A.; Labrada, R. E.; Landes, M.; Kudsk, P.; Streibig, J. C.].
AU: Harley, K. L. S. \ Julien, M. H. \ Wright, A. D.
YR: 1996
PP: 639-644
BN: ISBN 87-984996-1-0
LA: En
MS: 16 ref.
AA: Division of Entomology, CSIRO Australia, PMB No. 3 Indooroopilly, Brisbane, Queensland 4068, Australia.
AB: An account is given of the problems and control of Eichhornia crassipes. Problems are particularly severe in the equatorial zone. Biological control has been carried out with Neochetina bruchi, N. eichhorniae and Sameodes albiguttalis. Herbicides that have been used included 2,4-D, diquat and glyphosate, and physical control has included removal of the plants and the use of floating diversion booms. A reduction of nutrients inputs into water bodies is needed to reduce the rate of growth. Sustainable management strategies for control must prioritize infestations and integrate methods of control.
DE: conferences \ international weed control congress \ Eichhornia crassipes \ weed control \ chemical control \ 2,4-D \ diquat \ glyphosate \ biological control \ Neochetina bruchi \ Neochetina eichhorniae \ Sameodes albiguttalis \ physical control \ aquatic weeds \ nutrients
AN: 0W04700827 \ 0E08602909

TI: Status of biocontrol research on water hyacinth abroad.
AU: Chen ZhiQun
JN: Chinese Journal of Biological Control
YR: 1996
VL: 12
NO: 3
PP: 143-145
LA: Ch
MS: 25 ref.
AA: Institute of Biological Control, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
AB: Research on the biological control of water hyacinth (Eichhornia crassipes) outside China was reviewed. The extent to which control has been developed in other countries and the natural enemies being investigated were considered. Among the natural enemies discussed were the insects Neochetina bruchi, N. eichhorniae, Bellura densa, Haimbachia infusella, Sameodes albiguttalis and Orthogalumna terebrantis, and the fungus Cercospora rodmanii.
DE: weed control \ aquatic weeds \ weeds \ noctuidae \ acari \ Eichhornia crassipes \ biological control \ Neochetina bruchi \ Neochetina eichhorniae \ Bellura densa \ Haimbachia infusella \ Sameodes albiguttalis \ Orthogalumna terebrantis \ Cercospora rodmanii \ control
AN: 0W04700407 \ 0E08602908 \ 7E01901057

TI: An evaluation of hydrophilic polymers for formulating the bioherbicide agents Alternaria cassiae and A. eichhorniae.
AU: Shabana, Y. M. \ Charudattan, R. \ DeValerio, J. T. \ Elwakil, M. A.
JN: Weed Technology
YR: 1997
VL: 11
NO: 2
PP: 212-220
LA: En
MS: 18 ref.
AA: Plant Pathology Department, Faculty of Agriculture, Mansoura University, El-Mansoura, Egypt.
AB: Eight polymers capable of forming aqueous gels were compared for their capacity to retain hydration over time, to promote spore germination, and to rolong the viability of germinated spores (germlings) of Alternaria cassiae, a bioherbicide agent for sicklepod (Senna obtusifolia [Cassia obtusifolia]) control. When compared at a standard 0.1% w/w (gel/water) concentration, the eight gels retained hydration for 6 d with no significant differences among them in the rate of dehydration. The best concentration of each gel that yielded 95 to 100% spore germination within 6 h after hydration was then chosen, and the gels were compared at these concentrations to determine the duration of effectiveness of the gels. The effectiveness was rated on the basis of the proportions of alive germlings versus germinated spores and alive germlings versus total spores, determined with the aid of a fluorescent vital stain. Based on these two parameters, the most effective gel was Kelzan^® xanthan gum. However, all gels supported >50% alive germlings over a period of 1 week, suggesting that the addition of any of these polymers to the inoculum suspension should enable the fungal propagules to remain moist for a prolonged period, benefit from the high ambient moisture to improve germination, and promote disease development. Accordingly, seven of these gels were tested for their ability to enhance pathogenicity of a mycelial inoculum of A. eichhorniae, a bioherbicide agent for water hyacinth (Eichhornia crassipes). Gellan gum and Kelgin^® -HV were most effective in promoting disease, followed by Evergreen^® 500 polyacrylamide, and Kelgin^® -LV. Metamucil^®, Kelzan^® xanthan gum and N-Ge^(TM) were no better than the control inoculum without any gel. Thus, the gels may have differential effects on different fungi and inoculum types. Nonetheless, the results confirm the utility and feasibility of hydrophilic gels as formulating materials for bioherbicides.
DE: alginates \ cellulose \ polyacrylamide \ hydrophilic polymers \ evaluation \ alternaria \ plant pathogenic fungi \ aquatic weeds \ weed control \ alternaria \ mycoherbicides \ herbicides \ application \ formulations \ Alternaria cassiae \ Alternaria eichhorniae \ Cassia obtusifolia \ Eichhornia crassipes \ biological control \ fungi \ control \ weeds \ weeds
AN: 0W04604829 \ 0M07700757 \ 7E01901024

TI: Prospects for the use of phytotoxic metabolite of Alternaria eichhorniae to control aquatic weeds.
AU: Kamanna, B. C. \ Ponnappa, K. M.
JN: Crop Research (Hisar)
YR: 1996
VL: 12
NO: 1
PP: 11-14
LA: En
MS: 11 ref.
AA: Department of Plant Pathology, University of Agricultural Sciences, G. K.V. K., Bangalore-560 065, India.
AB: An experiment was carried out to study the phytotoxicity of the metabolite solution or crude toxin of A. eichhorniae (which causes blight of Eichhornia crassipes) on 19 aquatic weed species from 15 families. Phytotoxic symptoms were produced on most of the plants tested. This shows that the phytotoxin produced by the fungus is not host-specific and it may be useful in the control of floating aquatic weeds.
DE: plant pathogenic fungi \ alternaria \ Eichhornia crassipes \ host plants \ Alternaria eichhorniae \ weeds \ fungi \ weed control \ aquatic weeds \ biological control \ fungi \ control
AN: 0W04603316

TI: Update on biological control of water hyacinth in Papua New Guinea.
AU: Orapa, W. \ Atip, C.
JN: Didimag Newsletter
YR: 1996
VL: 28
NO: 9-12
PP: 28-30
LA: En
AA: APD <dash> DAL, Kila Kila, Papua New Guinea.
AB: A report on the Papua New Guinea Department of Agriculture and Livestock/Australian AID biological control project for Eichhornia crassipes is presented. Problems encountered in implementing the first phase of the project (Jan. 1993-Dec. 1995) are summarized. The weed was more widespread than originally thought, and surveys and releases in all infested areas could not be completed given the budgetary and time constraints. An extension to the project (Jan. 1996-Dec. 1998) was agreed and the programme is outlined, including the possible introduction of Acigona infusella [Haimbachia infusella] (currently held in quarantine) and the mirid Eccritotarsus catarinensis, improving the work base, providing training, and increasing public awareness. The results of surveys conducted in the Sepik river system since 1992 are summarized. There is evidence of permanent control, particularly by Neochetina eichhorniae. While N. eichhorniae and N. bruchi are established in the Sepik, the latter is not yet widely dispersed.
DE: aquatic weeds \ weeds \ geographical distribution \ surveys \ biological control agents \ Miridae \ Papua New Guinea \ Eichhornia crassipes \ biological control \ research \ biological control \ insects \ control \ Haimbachia infusella \ Eccritotarsus catarinensis \ Neochetina eichhorniae \ Neochetina bruchi \ weed control \ biological control \ biological control \ weeds \ control \ control \ biological control \ weeds \ control \ against \ biological control \ biological control \ biological control
GL: Papua New Guinea
AN: 0W04602912 \ 7E01801911 \ 7S02303315 \ 0S06012648 \ 0E08511948

TI: Effect of designed mycoherbicide prepared from host-specific candidate, Alternaria eichhorniae on some physiological and ultrastructural characteristics of waterhyacinth.
AU: Shabana, Y. M. \ Baka, Z. A. M. \ Abdel-Fattah, G. M.
JN: Annals of Agricultural Science (Cairo)
YR: 1996
VL: 41
NO: 1
PP: 421-443
LA: En
LS: ar
MS: 43 ref.
AA: Plant Pathology Dept., Faculty of Agriculture, Univ. of Mansoura, Egypt.
AB: A comparative study on the mycoherbicidal efficacy of different alginate formulations of Alternaria eichhorniae 5 (isolate Ae5), a virulent Egyptian isolate, on water hyacinth (Eichhornia crassipes) was conducted. The fungus was formulated as alginate pellets containing mycelium alone, mycelium + culture filtrate, or culture filtrate alone. Each formulation was applied with and without a hydrophilic humectant (Evergreen 500). These formulations were evaluated for disease incidence (DI) and disease severity (DS). The maximum DS was obtained by using alginate pellets containing mycelium + culture filtrate. Alginate formulations supplemented with the hydrophilic polymer were more effective in promoting pathogenicity. Some physiological changes associated with treated plants were determined 3, 6 and 9 days post-treatment. Plants inoculated with alginate pellets of mycelium + culture filtrate had the lowest levels of pigments, carbohydrates and relative water content. Infection led to an increase in the total phenol content of leaves compared with the untreated control. Water hyacinth leaves treated with the alginate formulation of mycelium + culture filtrate were examined using scanning and transmission electron microscopy. Penetration into leaves by the fungus occurred through the stomata only. Invading hyphae were located in the intracellular spaces of leaf tissues. Cytological changes noted in infected cells included gross changes in chloroplasts, the nucleus and mitochondria. Invagination of the plasma membrane, particularly at the plasmodesmata, was also observed. The association between the infection process, physiological disorder and the ultrastructure of infected leaves is discussed.
DE: weeds \ herbicides \ weed control \ aquatic weeds \ mycelium \ plant physiology \ carbohydrates \ phenols \ leaves \ stomata \ cytology \ chloroplasts \ mitochondria \ plasmodesmata \ Alternaria \ mycoherbicides \ Eichhornia crassipes \ biological control \ fungi \ control \ Alternaria eichhorniae \ weed biology \ plant composition \ plant pigments \ plant morphology \ formulations \ pellets \ interactions \ hydrophilic polymers \ control \ against \ evaluation \ biological control agents
AN: 0W04602482 \ 7E01801910

TI: Strategies for waterhyacinth (Eichhornia crassipes) control in Mexico.
CT: Management and ecology of freshwater plants. Proceedings of the 9th international symposium on aquatic weeds, European Weed Research Society, Dublin, Irish Republic, 1994 [edited by Caffrey, J. M.; Barrett, P. R. F.; Murphy, K. J.; Wade, P. M.].
AU: Gutiérrez, E. \ Huerto, R. \ Saldaña, P. \ Arreguín, F.
JN: Hydrobiologia
YR: 1996
VL: 340
NO: 1/3
PP: 181-185
LA: En
MS: 9 ref.
AA: Hydrobiology Laboratory, Instituto Mexicano de Tecnología del Agua, Apdo. P. 235, CIVAC, Morelos, 62500, Mexico.
AB: Under a national programme to control the water hyacinth in Mexico, guidelines to deal with the related ecological, social, technical and economic factors, and specific strategies to reduce coverage of the weed, were developed. The ecological factors which were noted include the identification of the most affected areas and the consequences of proposed treatments. The social aspects embrace the stimulation of user awareness as to the importance of water quality, the creation of organizations to coordinate user-sponsored control activities, and the awakening of a community identity. Basic to all are the technical and economic aspects which make the activities feasible and operational. Examples are given of control by means of water level management, mechanical methods using trituration, and the application of chemical and biological agents, all of which may be combined in an integral programme.
DE: eichhornia crassipes \ control \ management \ mexico \ weeds \ weed control \ aquatic weeds \ plant ecology \ water quality \ organizations \ economics \ cultural control \ mechanization \ herbicides \ biological control \ integrated control \ International symposium on aquatic weeds \ Management and ecology of freshwater plants \ European Weed Research Society \ conferences
GL: Mexico
AN: 0W04602474

TI: Biological control of weeds in Argentina: progress and actual situation, two decades after its initiation.
FT: Control biológico de malezas en la Argentina: progresos y situación actual, a dos décadas de su comienzo.
CT: El control biologico en America Latina: Actas de la "III Mesa Redonda de Control Biologico en el Neotropico", Rio de Janeiro, Brasil, 12-16 de agosto de 1991 [edited by Zapater, M. C.].
AU: Cordo, H. A.
YR: 1996
PP: 9-15
BN: ISBN 950-43-7227-9
LA: Es
LS: en
MS: 23 ref.
AA: Lab. de Control Biológico de Malezas, USDA, ARS, 1686 Hurlingham, Buenos Aires, Argentina.
AB: The biological control of weeds in Argentina since 1970 is discussed. Eight species of natural enemies have been imported (1 fish, 5 insects, 1 mite and 1 fungus) for the control of 6 weed species (Myriophyllum aquaticum, Potamogeton spp., Chara spp., Prosopis ruscifolia, Carduus thoermeri and Chondrilla juncea). A native insect was utilized for the control of Eichhornia crassipes. The following have been achieved: control of E. crassipes in the Dique Los Sauces reservoir; establishment and dispersal of Rhinocyllus conicus on Carduus spp.; and establishment and dispersal of Eriophyes chondrillae [Aceria chondrillae] and Puccinia chondrillina on Chondrilla juncea. However, the only ongoing project is the use of fish for the control of aquatic weeds.
DE: biological control agents \ natural enemies \ aquatic weeds \ Argentina \ Eichhornia crassipes \ Myriophyllum aquaticum \ Potamogeton \ Chara \ Prosopis ruscifolia \ Carduus thoermeri \ Chondrilla juncea \ control \ biological control \ biological control \ Acari \ insects \ herbivorous fishes \ fungi \ Rhinocyllus conicus \ Eriophyes chondrillae \ Puccinia chondrilina \ control \ weeds \ conferences \ Biological control in Latin America \ weed control \ biological control \ eriophyes \ puccinia \ control \ biological control \ biological control \ control \ weeds \ biological control \ weeds \ biological control \ biological control \ weeds \ Carduus \ control \ biological control \ control \ control \ Carduus \ Aceria chondrillae \ control \ control \ biological control \ against \ weeds \ weeds \ biological control
GL: Argentina
AN: 0W04601667 \ 0E08504937 \ 7E01801875

TI: The training programme for the Water Users' Associations in Mexico.
FT: La formation continue des associations d'usagers de l'eau au Mexique.
CT: Sustainability of irrigated agriculture ­ farmers' participation towards sustainable agriculture: volume 1-B. Transactions of the 16th International Congress on Irrigation and Drainage, Cairo, Egypt, 1996 [edited by Nicholaichuk, W.].
AU: Rendón-Pimentel, L. \ Guillén-González, J. A. \ Mosqueda-Badillo, R.
YR: 1996
PP: 495-504
LA: Fr
LS: en
AA: IMTA, Paseo Cuauhnáhuac 8532, Jiutepec, Morelos 62550 Mexico.
AB: Mexico's National Water Commission (CNA) transferred 2600000 ha of irrigated land to 340 Water Users Associations from 1990 to 1994. Today the WUAs collect the water fees, and administrate, operate, and maintain the transferred irrigation districts. Prior to reception of the irrigation districts, the WUAs created the administrative, operation, and maintenance departments. The CNA started a training and technology transfer programme for WUA managers and technicians and CNA technicians to support the transfer of irrigation districts. The results of three projects developed for late transfers are presented: (1) weed control in channels and drains in one of the most important maintenance problems in irrigation districts. The most prominent plants are water hyacinth (Eichhornia crassipes) and hydrilla (Hydrilla verticillata). To control 'Eichhornia sp'., the insects Neochetina bruchi and N. eichhorniae were introduced in Irrigation District 010. Twelve strategic points were chosen to free 12850 insects from May 1995 to January 1996. Taking into account the relative growth of Neochetina spp. and Eichhornia sp., this weed will be controlled by March 1997. The grass carp (Ctenopharyngodon idella) was used to control Hydrilla sp. This was done after cutting hydrilla with heavy chains. At the moment, hydrilla is under biological control. The weed control programme was financed by the water associations. (2) The minor irrigation network and on-farm irrigation improvement consists of changing unlined channel by low pressure plastic pipe. In Irrigation District 076, a collective irrigation network for 11 plots was designed and constructed considering these technologies. After 5 irrigations a 34% water saving had been achieved as well as 25% increase in yield. (3) In the Carrizo irrigation district, 22 ha of salty soils were reclaimed by installing drainage at 25 and 50 m spacing. Four irrigations were applied before seeding wheat to leach salts from the soil. Crop yields were 25% more than the local average.
DE: irrigation \ water resources \ drainage \ irrigation water \ management \ weeds \ weed control \ education \ education programmes \ Mexico \ aquatic weeds \ conferences \ International congress on irrigation and drainage \ Sustainability of irrigated agriculture - farmers' participation towards sustainable agriculture \ Eichhornia crassipes \ Hydrilla verticillata \ irrigation channels \ non-farm land \ biological control \ physical control \ insects \ control \ Neochetina bruchi \ Neochetina eichhorniae \ Ctenopharyngodon idella \ herbivorous fishes \ control \ cutting \ control
GL: Mexico
AN: 0S06002944 \ 7S02300915 \ 0W04601668

TI: Biological control of water hyacinth.
AU: Holtkamp, R.
JN: Agnote - NSW Agriculture
YR: 1996
NO: No. 2/092
PP: 2 pp.
LA: En
AA: Weed Biological Control Unit, Tamworth, New South Wales, Australia.
AB: With special reference to biological control of the weed in Australia, notes are provided on the injuriousness and control of the aquatic weed Eichhornia crassipes. Neochetina eichhorniae and Sameodes albiguttalis were introduced into Australia in 1975 and 1977, resp., and were released at sites ranging from Ingham in North Queensland to Sydney and Mores in New South Wales. Both species established readily and most weed infestations in New South Wales and Queensland are under attack. N. bruchi was only recently introduced into Australia and was first released in limited numbers in 1990.
DE: natural enemies \ Eichhornia crassipes \ biological control \ weeds \ control \ Neochetina eichhorniae \ Sameodes albiguttalis \ Neochetina bruchi \ control \ against \ Australia \ New South Wales \ Queensland \ insects \ control \ weed control \ control
GL: Australia \ New South Wales \ Queensland
AN: 0E08509951 \ 0W04604987 \ 7E01802671

TI: Alternaria eichhorniae, a biological control agent for water hyacinth: mycoherbicidal formulation and physiological and ultrastructural host responses.
AU: Shabana, Y. M. \ Baka, Z. A. M. \ Abdel-Fattah, G. M.
JN: European Journal of Plant Pathology
YR: 1997
VL: 103
NO: 2
PP: 99-111
LA: En
MS: 45 ref.
AA: Department of Plant Pathology, Faculty of Agriculture, University of Mansoura, Egypt.
AB: The bioherbicidal efficacy of different alginate formulations of A. eichhorniae 5, a virulent Egyptian isolate, was compared on water hyacinth (Eichhornia crassipes). The fungus was formulated as alginate pellets containing mycelium alone, mycelium plus culture filtrate or culture filtrate alone. Each formulation was applied with and without a hydrophilic humectant (Evergreen 500). These formulations were evaluated for disease incidence and disease severity. Maximum disease severity occurred with the alginate pellets of mycelium plus culture filtrate. Alginate formulations supplemented with the hydrophilic polymer were more effective in promoting disease. Physiological changes associated with the treated plants were determined 3, 6 and 9 d after treatment. Plants treated with alginate pellets of mycelium plus culture filtrate had the lowest levels of pigments, carbohydrates and relative water content. Infection with A. eichhorniae 5 significantly increased total phenol contents of leaves compared with the controls. Penetration of leaves by A. eichhorniae 5 only occurred through the stomata, and the invading hyphae were located in the intercellular spaces of leaf tissues. Cytological changes in infected cells included changes in chloroplasts, nucleis and mitochondria. Invagination of the plasma membrane, particularly at plasmodesmata, also occurred in infected cells. The associations between the infection process, the physiological disorder and the ultrastructure of infected leaves are discussed.
DE: aquatic weeds \ weed control \ biological control agents \ plant diseases \ plant pathogens \ plant pathogenic fungi \ Eichhornia crassipes \ Alternaria eichhorniae \ biological control \ host parasite relationships \ ultrastructure \ biological control \ weeds \ biological control \ fungi \ mycoherbicides \ control \ biological control \ formulations
AN: 0M07610202 \ 0W04700370 \ 7E01900386

TI: The integrated control of water hyacinth, Eichhornia crassipes, in Africa based on Roundup^® herbicide treatments.
CT: Proceedings of the 9th international symposium on biological control of weeds, Stellenbosch, South Africa, 19-26 January 1996 [edited by Moran, V. C.; Hoffmann, J. H.].
AU: Findlay, J. B. R. \ Jones, D.
YR: 1996
PP: 435-440
BN: ISBN 0-7992-1759-X
LA: En
MS: 30 ref.
AA: Agricultural Resource Consultants, P.O. Box 3474, Parklands 2121, South Africa.
AB: The favourable environmental impact characteristics of Roundup (360 g glyphosate per litre) have been extensively researched and this has resulted in this product being widely used for the control of water hyacinth. Successful control programmes have been based on a Roundup spray followed by regular spot-spraying, mechanical or hand removal and, more recently, the utilization of biological controlagents such as insects, mites and diseases. Initially, herbicide is applied from aircraft, but follow-up treatments are applied by spray teams in boats and from the shoreline. It is critical for a control programme to be implemented which will also allow for biocontrol agents to remain established in the area. Detailed analyses on the impact of herbicide use on this water weed have been conducted in South Africa, Nigeria and Zimbabwe, with the conclusion that there is very little or no adverse effect on water quality.
DE: weeds \ weed control \ aquatic weeds \ conferences \ International symposium on biological control of weeds \ Eichhornia crassipes \ control \ chemical control \ integrated control \ biological control \ physical control \ glyphosate \ control \ application \ environmental impact \ mechanization \ manual weed control \ Africa \ application methods \ herbicides \ aerial application \ insects \ Acari \ plant diseases \ control \ South Africa \ Nigeria \ Zimbabwe \ residues \ water \ water quality \ biological control \ biological control agents \ beneficial arthropods \ control \ arthropods \ plant pathogens \ integrated pest management \ control
GL: Africa \ South Africa \ Zimbabwe \ Nigeria
AN: 0W04505005 \ 0E08502930 \ 7E01800417

TI: The importance of biological control for the reduction of the incidence of major weeds in developing countries.
CT: Proceedings of the 9th international symposium on biological control of weeds, Stellenbosch, South Africa, 19-26 January 1996 [edited by Moran, V. C.; Hoffmann, J. H.].
AU: Labrada, R.
YR: 1996
PP: 287-290
BN: ISBN 0-7992-1759-X
LA: En
MS: 11 ref.
AA: Plant Protection Service, United Nations Food and Agriculture Organization, Via del Terme di Cacracalla, 000100 Rome, Italy.
AB: Weeds can cause up to 10% of crop losses in agriculturally developed countries, while in the developing world this figure could be two or more times higher. Several weed problems caused by intensive monocropping or repeated use of a particular herbicide are very difficult to resolve using a single control method. Crop losses and other cropping problems caused by weeds make weed management the most important activity within an integrated crop management scheme. The development of sustainable agriculture requires the judicious use of several practices that are integrated and compatible with pest control. Biological control should play a major role in reducing the incidence of prevailing weed species with an integrated pest management (IPM) system. In tropical and sub-tropical areas all over the world there are several weed species causing serious crop losses. These are: Striga spp. in cereals and cowpea crops in Africa south of the Sahara; Orobanche in vegetables, legumes and sunflowers in northern Africa and the Near [Middle] East region; Rottboellia cochinchinensis in various food and industrial crops in Central and South America, including the Caribbean; and water hyacinth (Eichhornia crassipes) in various tropical countries of Latin America, Africa and Southeast Asia. The development of technically sound and economically feasible biological control of these and other major species would be of great help to farmers in the developing world. The Food and Agriculture Organization (FAO) of the United Nations, within its Special Action Programme on IPM, gives priority to the development of IPM in crop production, and improved weed management is one of the major components of this effort.
DE: crop losses \ herbicides \ vigna unguiculata \ helianthus annuus \ weeds \ parasitic weeds \ aquatic weeds \ conferences \ International symposium on biological control of weeds \ developing countries \ weed control \ biological control \ integrated control \ herbicide resistant weeds \ cereals \ cowpeas \ Striga \ host parasite relationships \ Africa \ Orobanche \ Rottboellia cochinchinensis \ Eichhornia crassipes \ control \ biological control \ biological control \ vegetables \ legumes \ sunflowers \ biological control \ Central America \ South America \ Caribbean \ North Africa \ Middle East \ Latin America \ South East Asia \ biological control \ biological control \ crops \ food crops \ industrial crops \ America \ biological control \ control \ biological control \ biological control
GL: Developing countries
AN: 0W04504809 \ 6T01400775 \ 7E01800343

TI: International co-operation and linkages on the management of water hyacinth with emphasis on biological control.
CT: Proceedings of the 9th international symposium on biological control of weeds, Stellenbosch, South Africa, 19-26 January 1996 [edited by Moran, V. C.; Hoffmann, J. H.].
AU: Julien, M. H. \ Harley, K. L. S. \ Wright, A. D. \ Cilliers, C. J. \ Hill, M. P. \ Center, T. D. \ Cordo, H. A. \ Cofrancesco, A. F.
YR: 1996
PP: 273-282
BN: ISBN 0-7992-1759-X
LA: En
MS: 11 ref.
AA: CSIRO Division of Entomology, Private Bag 3, Indooroopilly 4068, Australia.
AB: Water hyacinth (Eichhornia crassipes) remains the world's most important aquatic weed. It is spreading at an alarming rate in Africa and Papua New Guinea and is a major problem in the Indian sub-continent and South East Asia. Successful biological control can significantly reduce weed cover 3-10 years after establishment of agents and has achieved excellent control in a number of countries. Information on biological control technology has been widely-disseminated but the rate of application has been relatively slow due to a lack of experienced practitioners in some developing countries and because adequate funding has not been available. Recently, due to the rapid increase in the abundance and distribution of this weed in Africa and elsewhere, interest in the problem has widened and the number of control projects is increasing. The major organizations involved in conducting or supporting research on biological control of water hyacinth (CSIRO in Australia, PPRI in South Africa and USDA in the USA) are studying additional control agents. They are also investigating the integration of biological and other control techniques into efficient management strategies. This paper describes these organizations' interactions and co-operation which promote efficient use of scarce resources and outlines their world-wide linkages with other agencies and national governments to further extend the application of this technology.
DE: information \ weeds \ aquatic weeds \ organizations \ conferences \ International symposium on biological control of weeds \ Eichhornia crassipes \ control \ biological control \ biological control \ ecology \ spread \ Africa \ Papua New Guinea \ South East Asia \ India \ biological control \ control \ biological control \ biological control
GL: Africa \ Papua New Guinea \ South East Asia \ India
AN: 0W04505002 \ 7E01800415

TI: Initiating the use of fungi for biocontrol of weeds in Malaysia.
CT: Proceedings of the 9th international symposium on biological control of weeds, Stellenbosch, South Africa, 19-26 January 1996 [edited by Moran, V. C.; Hoffmann, J. H.].
AU: Caunter, I. G. \ Lee, K. C.
YR: 1996
PP: 249-252
BN: ISBN 0-7992-1759-X
LA: En
MS: 19 ref.
AA: School of Biological Sciences, University Sains Malaysia, 11800 Penang, Malaysia.
AB: An account is given of the progress, problems and future directions in the use of indigenous fungi as biocontrol agents of weeds in Malaysia. Three weed species are highlighted. Eichhornia crassipes, the major weed problem of rice-field irrigation and drainage canals is mainly diseased by Myrothecium roridum. The broad host range of this fungus precludes the efficacy of the introduced weevil, Neochetina eichhorniae. The weevil on its own has thus far failed to establish effectively and to suppress the weed population. The integration of these two agents is discussed. More recently, an Alternaria sp. similar to A. eichhorniae has been isolated. Results on the preliminary assessment of this isolate are presented. Sphenoclea zeylanica is an important broadleaved weed in rice fields. An isolate of Colletotrichum gloeosporioides [Glomerella cingulata], which is pathogenic on this weed, was recently obtained. Spore concentrations of 2×10⁶/ml can cause complete kill within a week to 10 days. Disease severity is affected by both plant age and dew period. Limited host range testing indicates the host specificity of the isolate. Mikania micrantha is a serious weed of plantation crops. Most stands of this weed are infected by Cercospora mikaniicola. Particular problems with this pathogen are poor sporulation in culture and slow disease development. The effects of nutrients on spore germination and their relationship to disease severity are discussed.
DE: myrothecium roridum \ plant pathogenic fungi \ neochetina eichhorniae \ alternaria \ alternaria eichhorniae \ oryza sativa \ host specificity \ cercospora mikaniicola \ spore germination \ nutrients \ plant diseases \ alternaria eichhorniae \ alternaria \ glomerella cingulata \ cercospora mikaniicola \ cercospora \ weeds \ weed control \ aquatic weeds \ conferences \ International symposium on biological control of weeds \ Malaysia \ biological control \ Eichhornia crassipes \ Sphenoclea zeylanica \ Mikania micrantha \ Sphenoclea zeylanica \ control \ biological control \ fungi \ insects \ control \ rice \ drainage channels \ biological control \ mycoherbicides \ fungi \ control \ biological control \ biological control \ plantation crops \ fungi \ control \ biological control \ control \ biological control \ fungi \ control \ biological control \ fungi \ control \ biological control \ biological control \ fungi \ control \ biological control agents \ biological control \ control \ control \ interactions \ beneficial insects \ biological control \ control \ against \ biological control \ evaluation \ International bioherbicide workshop \ biological control \ biological control \ biological control \ biological control \ biological control \ biological control \ biological control
GL: Malaysia
AN: 0W04504808 \ 0M07601717 \ 0E08502928 \ 7E01800342 \ 7U02000284

TI: Fungal pathogens of some Brazilian aquatic weeds and their potential use in biocontrol.
CT: Proceedings of the 9th international symposium on biological control of weeds, Stellenbosch, South Africa, 19-26 January 1996 [edited by Moran, V. C.; Hoffmann, J. H.].
AU: Barreto, R. W. \ Evans, H. C.
YR: 1996
PP: 121-126
BN: ISBN 0-7992-1759-X
LA: En
MS: 19 ref.
AA: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, 36571-000, MG, Brazil.
AB: A survey was undertaken in the state of Rio de Janeiro, Brazil, to investigate the fungal pathogens associated with the following seven aquatic weeds: Eichhornia crassipes, E. azurea, Echinochloa polystachya, Paspalum repens, Pistia stratiotes, Polygonum spectabile and Typha dominguensis [T. domingensis]. Amongst the fourteen pathogens found, five are considered to represent new species, whilst the remainder are either new host and/or country records, which reflect the paucity of knowledge on the mycobiota of aquatic weeds. In addition, a list of purported pathogens associated with water hyacinth (Eichhornia crassipes) world-wide is presented, compiled from a literature and herbarium search. The few records of coevolved pathogens, compared with exotics, suggests that future surveys should be better targeted within the neotropical range of water hyacinth. The biocontrol potential of the fungi collected is discussed.
DE: eichhornia \ paspalum \ polygonum \ weeds \ aquatic weeds \ herbaria \ surveys \ weed control \ weeds \ conferences \ International symposium on biological control of weeds \ Eichhornia crassipes \ Eichhornia azurea \ Echinochloa polystachya \ Paspalum repens \ Pistia stratiotes \ Polygonum spectabile \ Typha domingensis \ hosts \ fungi \ Brazil \ Rio de Janeiro \ weed hosts \ plant pathogens \ control \ biological control \ biological control \ control \ pathogens \ pathogens \ biological control \ biological control
GL: Brazil \ Rio de Janeiro
AN: 0W04504974 \ 7E01702711 \ 0M07603322

TI: Biological control efforts towards the management of some common weeds in Malaysia.
CT: Proceedings of the symposium on biology and management of weeds and fourth tropical weed science conference, Bogor, Indonesia, 22-24 November 1994 [edited by Tjitrosemito, S.; Soerianegara, I.].
AU: Ismail, A. A.
JN: BIOTROP Special Publication
YR: 1996
NO: No. 58
PP: 149-157
LA: En
MS: 22 ref.
AA: Malaysian Agricultural Research & Development Institute, Kuala Lumpur, Malaysia.
AB: A brief review of the past work and progress in biological control is presented for the following weed species: Chromolaena odorata, Cordia curassavica, Mikania micrantha, Salvinia molesta, Eichhornia crassipes and Mimosa pigra.
DE: reviews \ weed control \ woody weeds \ aquatic weeds \ conferences \ Tropical weed science conference \ Biology and management of weeds \ Chromolaena odorata \ Cordia curassavica \ Mikania micrantha \ Salvinia molesta \ Eichhornia crassipes \ Mimosa pigra \ control \ biological control \ Malaysia \ control \ weeds \ control \ weeds
GL: Malaysia
AN: 0W04503673 \ 7E01702000 \ 0F05707681

TI: Recent status of Neochetina eichhorniae on waterhyacinth and canna in West Java.
CT: Proceedings of the symposium on biology and management of weeds and fourth tropical weed science conference, Bogor, Indonesia, 22-24 November 1994 [edited by Tjitrosemito, S.; Soerianegara, I.].
AU: Kasno \ Tjitrosoedirdjo, S. S. \ Sunjaya \ Aryanti, N. S.
JN: BIOTROP Special Publication
YR: 1996
NO: No. 58
PP: 129-135
LA: En
MS: 3 ref.
AA: Faculty of Forestry, Bogor Agriculture University, Bogor, Indonesia.
AB: Feeding preference tests were carried out for mottled water hyacinth weevil (Neochetina eichhorniae) on ginger (Zingiber officinale), turmeric (Curcuma domestica [C. longa]), galangal (Kaempferia galanga), and red leaved and green leaved edible canna (Canna edulis). Water hyacinth (Eichhornia crassipes) was used as the control. Under the free choice condition, the weevil fed on water hyacinth and edible canna leaves; however, water hyacinth was much preferred over edible canna. Further survival tests on edible canna plants indicated that adult weevils may survive by feeding on canna plants; however, the weevil will not undergo is complete life cycle on canna plants. Therefore, edible canna plants will only be a temporary alternative host for N. eichhorniae adults. A field survey in West Java showed that N. eichhorniae was found in Bogor, Jakarta, Karawang, Sukamandi, Subang and Purwakata. The role of the weevil in controlling water hyacinth is only minor.
DE: Neochetina eichhorniae \ ginger \ Zingiber officinale \ turmeric \ Curcuma longa \ Kaempferia galanga \ Canna edulis \ weed control \ aquatic weeds \ life cycle \ hosts \ surveys \ feeding preferences \ geographical distribution \ plant pests \ insect pests \ conferences \ Tropical weed science conference \ Biology and management of weeds \ Eichhornia crassipes \ control \ biological control \ insects \ control \ Indonesia \ weeds \ control \ against \ biology \ host specificity \ natural enemies \ food plants \ weeds \ control \ control
GL: Indonesia
AN: 0W04503734 \ 7E01702043 \ 0E08502923

TI: Effect of silt coverage of water hyacinth roots on pupation of Neochetina eichhorniae Warner and N. bruchi Hustache (Coleoptera: Curculionidae).
AU: Visalakshy, P. N. G. \ Jayanth, K. P.
JN: Biocontrol Science and Technology
YR: 1996
VL: 6
NO: 1
PP: 11-13
LA: En
MS: 3 ref.
AA: Division of Entomology and Nematology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore 560 089, India.
AB: Observations under field conditions in Bangalore, Karnataka, India, showed that release of Neochetina eichhorniae and N. bruchi brought about successful control of water hyacinth [Eichhornia crassipes] in water bodies where the plants were free-floating. However, in situations where the plants were partly anchored, suppression of the weed was achieved only 8 years after insect release. Studies carried out under glasshouse conditions, in which plants with free-floating and silt-covered roots were exposed to Neochetina spp., showed that fully grown larvae were incapable of pupating on silted roots of water hyacinth. This resulted in reduced adult emergence of N. eichhorniae and N. bruchi, indicating that delayed suppression of water hyacinth in silted tanks may be due to the low population build-up of the weevils.
DE: silt \ water \ insects \ beneficial insects \ biological control agents \ natural enemies \ Eichhornia crassipes \ Neochetina eichhorniae \ Neochetina bruchi \ India \ Karnataka \ Neochetina \ biological control \ weeds \ control \ control \ biology \ environmental factors \ aquatic weeds \ weed control \ control \ biological control \ biological control \ control \ biological control \ biological control \ control \ against \ evaluation
GL: India \ Karnataka
AN: 0W04503318 \ 0E08408936 \ 7E0170203926/