Current status on researches of biological invasion agents in Vietnam Don, Le Dinh

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Current status on researches of biological invasion agents in Vietnam
Don, Le Dinh

Department of Biotechnology, Department of Plant Protection, University of Agriculture and forestry Hochiminh City, Vietnam (

Viet Nam in Asian trade

Vietnam lies on the eastern part of Indochinese peninsula. Its coastline is 3,260km and inland border is 4,510km. The country has a long border with China in the north, with Laos and Cambodia in the west, and Pacific Ocean in the east and south. It is possible to enter Vietnam overland from either Cambodia, Laos, or China. Such makes easy exchanges of agriculture products among those countries and possible expanding a little far to Thailand and Myanmar on routes. There are many ways the agriculture products reaching to each country, it is by contracting between countries with products declared and others are by small volume, small business way, or smuggling with not declared at the Office. Normally Vietnam uses regulations just similar with international rules. In which, some changes are required to fix with country condition and with Vietnamese people, as specific issues of national. All of agriculture products including seeds, plant, soils, water which will be sent out or received from should be declared and checked for quarantine requires. The works gradually come to over in recent increasing of export-import activities or with long bode sides that make difficult to control the exotic agents which might enter together with only small volume agriculture products.

Free trade area forming to promote exchange of agriculture products more and more, beside several bilateral trade agreements signated between countries are challenges to plant quarantine officers to catch up and to reject immediately alien agents to protect the country. Vietnam Government recognizes dangerous impacts of alien agents to the country such as harmful impacts to the natural ecosystem and the safety of exported agriculture products. Therefore several regulations are formulated and stated. State Laws of Plant Protection and Quarantine revised proclaimed on July 2001 including 7 chapters and 45 articles. The regulation is a corner-stone for rejecting of alien agents to be able to enter the country. List of Biological Agents being objects for quarantine control was produced from the year of 2000, in which 27 insects, 15 pathogens, 7 nematodes, and 12 weeds have not been in Vietnam and not allowed to bring in. They should be completely killed as soon as entering the country. The Environmental Protection Laws promulgated from 1994 and a guidebook named as ‘List of Risk Biological Invasion Agents in the World’ published in 2002 are important documents for research activities and also for agricultural product trade among countries in the Asian or the world.

However, even the country has several laws and regulations, we also suffered with many exotic agents in the past and present too. They entered into the country a long time or a few years ago via intentional and accidental introductions. The exotic species caused several disorders to native habitats and to normal life of Vietnamese people. In this report, the information of four exotic agents by which agricultural activities of the country are changed or reconstructed will be summarized. They are Giant Mimosa plant, Golden Snail, Water Hyacinth, and Nutria.

Studies on biological invasion agents

Giant Mimosa plant, in Vietnamese called Cay Mai Duong, Mimosa pigra L. presents at many parts of Vietnam . They adapted to a wide range of ecosystems from highland to lowland areas. They have been found to sit intensively on riversides, small ponds and water reservoirs in the southern parts of Vietnam. For instance, at Tam Nong Bird Park located in Dong Thap province, called Tram Chim, is attacked by mimosa plants. The attacking happening is showed in following table.

Infection area with Giant mimosa plant in Tram Chim park


Infested area


First recorded


150 ha


490 ha


958 ha


1,700 ha /7,500 ha in total area

As called, Tram chim is leaving place of Red-headed Crane, a symbol of strength, longevity, and fidelity. Giant mimosa firstly attacked to marginal or abandoned fields in the park and after then intensively invaded to Crane inhabitation by growing over grass, a Crane’s food.

A research carried out by Thanh et al. (2003) indicated that Phloeospora mimosae Pigrae fungus and Carmenta mimosae insect might be used to control the Mimosa plants. Other methods recommended as cutting and burning, and herbicide use. Interestingly, the farmers find that goat likes to eat the Mimosa shoots leading to a recommendation to use the goat for controlling the mimosa. The farmer said that on average, one goat can eat 100-200 plants per day. However, the big problem nowadays is the Mimosa plants getting out of the water or humid places to spread over to roads and free places in cities and residences. Whatever methods the farmers use, the mimosa is a real challenge in future works of researchers, scientists, and leaderships at all levels in Vietnam.

Golden snail, Oc Buou Vang, Pomacea canaliculata is an example of alien species which was intentional introduced into Vietnam. As a good purpose, the golden snail was used as beneficial foods and taken care in limited and stricken areas. It became a major pest to the country as from it escaped out of the farmers due to intentional and unintentional release. An urgent needed to control them when thousands and thousands hectares of rice to be destroyed by snails and when river fishes in fields to be less and less because of pesticides sprayed. Snail is strong invasion and quickly spread forming pure stands anywhere from south to north of Vietnam. The state and local government have actively worked to prevent of the spread of Golden snail. From estimate, hundreds of billion dong Vietnam is spent to restrain the snails. Several methods have been suggested as follow:

+ Using chemical pesticides. (Not much approved)

+ Collecting and killing them anytime by using manual labourers. (approved)

+ Collecting and killing them by using traps. (approved)

+ Using dusts for killing. (Strong approved)

+ Using biological pesticides from phytotoxins. (On the way)

+ Using the snail as food for fishes. (excellent way)

In the Mekong delta, where is ordered to culture several kinds of river fish and shrimp, the farmers have found that the snails after pealing off the skin become a food source for fishes. Even though the hundreds of tones of snail used per day, that are nothing in the term of snail controlling. This is a story of past and present too.
Present of golden apple snail in Asian countries (Hal wart, 1994)


Year of infection


Year of infection





















Water Hyacinth, Boo Hot Ban, recorded in Vietnam in the 1930s. Nowadays no one recognizes it as an alien species because it is present over rivers, canals, ponds, and lacks, to sit nearby residential areas and to flood under house floor. Due to blocked with water hyacinth, Government has paid a lot of money for regularly cleaning the rivers, especially in Mekong delta at the rain season. Several methods are employed to kill and use water hyacinth such as:

+ To collect and cut off, then mixed with other materials forming manure


+ To collect and use as materials covering of base parts of fruit trees.

+ To cultivate at heavy polluted ponds for preventing of environmental

pollution. It is still a question.

+ To use making handicrafts for selling. It is a new benefit recently.

Nutria, Chuot Hai Ly in Vietnamese, Myocastor coypus is intentionally introduced into Vietnam with a purpose to culture for food using from the year of 2001. They were in strictly farms and increased the population very quickly. It was not easy to balance the risks and benefits or to pursue the farmers that nutria was dangerous alien animal. In that time, Department of Veterinary found that nutria was carrying of disease vectors to human. Fortunately in the year of 2002, Ministry of Agriculture and Rural Development has decided to kill all of them and said that importing of Nutria is illegal activities, whatever aims. It is a typical lesion on success of risk assessment. It seems that advance action is able to prevent the invasions of exotic species because the establishment stage is not occurred.

Several of plant species such as weeds and crops introduced into Vietnam have been permitted or might not, some of them were of high economic values when used as livestock feeds or as flowers; others were planted in private places. All of them are watching for risk assessments.
All of countries including Vietnam also have quarantine and monitoring systems based on rules and regulations which help to avoid accidental invasions of exotic species, and to monitor intentional cares. However, the systems can not completely control in context of Free Trade going on or because of expanding international air or over land transports and traveling through many neighbor countries of travelers. If it is true then what will happen in future? Should the agriculture development strategies of country be changed following colonization of exotic agents? How understanding the term of exotic agents in context of globe trade?
Constrains should be solved

+ Lacking of any concerning on Bio-Invasion agents at public level.

+ Lacking of education and training courses on Bio-Invasion agents for understanding their negative impacts on national biodiversity and exported agriculture products in global economy.

+ It is still a few laboratories involving in bio-invasion researches

+ Need of funding for establishing modern laboratories for quickly detection and identification of exotic agents.

+ Need of sharing information dealing with bio-invasion agents with other countries in Asian area and in the world.

Prospective researches

Vietnam is with country economic based on 80% agriculture products which are exported. The country has several conservative parks and diversity in ecosystems recognized at international level. Appearing and invasion of exotic agents will destroy the native ecosystems and alter the national typical products for exporting and diminish the attracting of foreign travelers. Researches on biological invasion agents should be focused on methods for identification of exotic agents as soonest, methods for assessment and management of environment risks, and update or renew the state laws often in order to legalize the regulations to the farmers. What can be done to avoid risks from exotic species? How to assess well the exotic species which are introduced into the country by accidental ways? To answer those questions is needed in prospective researches. Asian trade opened therefore cooperation researches between experts from Asian countries on biological invasion agents are also needed.


Endow, D.A., 2003. Biological invasions: assessment and management of environmental risk. FFTC-Extension Bulletin 538.

Kurokawa, S., 2001. Invasion of exotic weed seeds into Japan, mixed in imported feed grains.FFTC-Extension Bulletin 497.

Rahman, A., Popay, I., and James, T., 2003. Invasion plants in agro-ecosystems in New Zealand” Environmental impact and risk assessment. FFTC-Extension Bulletin 539.

Ngoc, H.K., 2002. Study on bionomics, damaging patterns of golden snail and on the efficacy of some golden snail control measures in HCMC. Master Thesis. University of Agriculture and Forestry Hochimih City, Vietnam. (asbtract in English).

Thanh, D.V.T., Cam, N.V., Thuy, L.T.T., Van, N.T., Hoat, T.X., Nguyen, N.H., 2003. Some results of studying Phloeospora mimosae Pigrae for controlling Mimosa pigrae L. Plant Protection Journal 2:32-36. (Abstract in English)

Plant Protection Journal, vol. 2, 2002 (in Vietnamese)

Plant Protection Journal, vol. 1, 2003 (in Vietnamese)

Plant Protection Journal, vol. 2, 2003 (in Vietnamese)

Plant Protection Journal, vol. 1, 2004 (in Vietnamese)

State Laws of Plant Protection and Quarantine, No. 11/2001/L/CTN, 2001 (in Vietnamese).

List of Plant Quarantine, No. 117/2000/QD/BNN-BVTV, 2000 (in Vietnamese).

Halwart, M., 1994. The golden apple snail in Asian rice farming systems: Present impact and future treat. International journal of pest management, 40: 199-206.

I would like to express my thanks to FFTC for invitation and financial support during the workshop. Thank to friends and students who were collected information on biological invasion agents in Vietnam.

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