{"id":13017,"date":"2026-06-20T12:26:13","date_gmt":"2026-06-20T12:26:13","guid":{"rendered":"https:\/\/dev.iita.org\/news-item\/scientists-send-weevils-after-water-hyacinth\/"},"modified":"2026-06-20T12:26:13","modified_gmt":"2026-06-20T12:26:13","slug":"scientists-send-weevils-after-water-hyacinth","status":"publish","type":"news-item","link":"https:\/\/iita.org\/fr\/news-item\/scientists-send-weevils-after-water-hyacinth\/","title":{"rendered":"Des scientifiques envoient des charan\u00e7ons contre la jacinthe d'eau"},"content":{"rendered":"

\"Image<\/a>
Two adult weevils munching on a water hyacinth.<\/figcaption><\/figure><\/p>\n\n\n\n

Researchers have released biological control agents\u2014Neochetina<\/em> et N. bruchi<\/em>\u2014 after water hyacinth in River Mono, Republic of Benin, in an effort to tackle the devastation caused by the water weed and free water ways for fishing and transport.<\/p>\n\n\n\n

The two biological agents, which are weevils, feed on only water hyacinth and have proved to be effective control agents of the water weed, according to Obinna Ajouno, a scientist with the International Institute of Tropical Agriculture.<\/p>\n\n\n\n

The released weevils were mass produced by the Department of Agriculture in Porto-Novo using start-up colony supplied by the International Institute of Tropical Agriculture that also provided technical assistance.<\/p>\n\n\n\n

Ajouno says today that the biocontrol exercise is the first of its kind by researchers in the Mono River to control the aquatic weed.<\/p>\n\n\n\n

Participants in the release which took place on 30 July 2010 included the Department of Agriculture, the National Coordination Unit of the Benin Economic Community of West African States\u2019 Water Weeds Project, the local communities and IITA.<\/p>\n\n\n\n

The project is part of the ongoing African Development Bank (AfDB) funded ECOWAS integrated project for the control of aquatic weeds involving physical removal, utilisation, and biological control methods.<\/p>\n\n\n\n

Alien to Africa, water hyacinth (Eichhornia crassipes<\/em>) often grows as floating plants or mats, as isl ands of plants floating freely on the water, or mixed with other vegetation on river banks. In nutrient-rich waters, such as in polluted ponds or lakes, it can grow so quickly that the surface covered by the mats doubles every four to seven days.<\/p>\n\n\n\n

The aquatic weed poses serious socioeconomic and environmental problems to<\/p>\n\n\n\n

\"Image<\/a>
Mono River infested by water hyacinth around Gr and-Popo. In the boat from left, Mr. Koudiko Didier a member of the local community, Mr. Adanve Gregoire and Mr. Houessinon Priam staff of the Department of Agriculture, releasing adult weevils on water hyacinth mat.<\/figcaption><\/figure><\/p>\n\n\n\n

millions of people in riparian communities and is, therefore, an added constraint to development. For instance, more than 12000 hectares of this weed infest Lake Victoria, affecting the livelihood of many of the more than 40 million people in Kenya, Tanzania, and Ug anda. The weed obstructs electricity generation, irrigation, navigation, and fishing; increases water loss resulting from evapotranspiration; and facilitates proliferation of such diseases as bilharzia.<\/p>\n\n\n\n

In Sudan alone, a partial evaluation of socioeconomic costs of water hyacinth, estimates that annual water loss from evapotranspiration over 300 km2 of canal would be enough to irrigate more than 400 ha. Effects on navigation in the Nile include 50 per cent higher running and maintenance costs and 30 per cent more use of fuel.<\/p>\n\n\n\n

The cost of chemical control alone over 15 years would have been in excess of 19 million United States dollars, according to the International Development Research Centre (IDRC). Until 2000, the Mono River which borders Togo was free of water hyacinth. Researchers are of the view that the weed might have been infested through human activities. Ajouno says the impact of these biological agents\u2014(weevils) \u2014 in the Mono River system in the years ahead will be monitored by regular field visits involving the collaborating institutions.<\/p>\n\n\n\n

###<\/b><\/p>\n\n\n\n

Pour plus d'informations, veuillez contacter :<\/p>\n\n\n\n

Obinna Ajouno, o.ajouno@cgiar.org<\/a>
IITA Scientist<\/p>\n\n\n\n

Jeffrey T. Oliver, o.jeffrey@cgiar.org<\/a>
Charg\u00e9 de communication d'entreprise (international)<\/p>\n\n\n\n

Godwin Atser, g.atser@cgiar.org<\/a>
Charg\u00e9 de la communication d'entreprise (Afrique de l'Ouest)<\/p>\n\n\n\n

IITA \u2013 Si\u00e8ge
Ibadan, Nig\u00e9ria<\/p>\n\n\n\n

\u00c0 propos de l'IITA<\/b>
L'Afrique a des probl\u00e8mes complexes qui minent l'agriculture et la vie des populations. Nous d\u00e9veloppons des solutions agricoles avec nos partenaires pour lutter contre la faim et la pauvret\u00e9. Notre [mot manquant ou \u00ab prim\u00e9 \u00bb] recherche pour le d\u00e9veloppement<\/a> repose sur une r\u00e9flexion cibl\u00e9e et faisant autorit\u00e9, ancr\u00e9e dans les besoins de d\u00e9veloppement de l'Afrique subsaharienne. Nous collaborons avec des partenaires en Afrique et au-del\u00e0 afin de r\u00e9duire les risques pour les producteurs et les consommateurs, d\u2019am\u00e9liorer la qualit\u00e9 et la productivit\u00e9 des cultures, et de g\u00e9n\u00e9rer de la richesse gr\u00e2ce \u00e0 l\u2019agriculture. L\u2019IITA est une organisation internationale \u00e0 but non lucratif d\u00e9di\u00e9e \u00e0 la recherche et au d\u00e9veloppement (R4D), cr\u00e9\u00e9e en 1967, dirig\u00e9e par un conseil d\u2019administration et soutenue principalement par le CGIAR<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"

Researchers have released biological control agents\u2014Neochetina and N. bruchi\u2014 after water hyacinth in River Mono, Republic of Benin, in an effort to tackle the devastation caused by the water weed and free water ways for fishing and transport.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}}},"tags":[],"science-area":[],"program":[],"location":[26],"news-type":[],"hub":[],"crop":[],"impact-areas":[],"item-year":[188],"class_list":["post-13017","news-item","type-news-item","status-publish","hentry","location-benin","item-year-188"],"yoast_head":"\nScientists send weevils after water hyacinth - 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