What is Chromolaena?
Differences between AWA and SA chromolaena
Other invasive alien plants within the Eupatorieae
History: A detailed history of this group has recently been published (Boller et al., 2006), of which a summary is provided here. During the 1st International Workshop on Biological Control and Management of Chromolaena odorata, held in Bangkok, Thailand in 1988, a recommendation was passed to establish an International Working Group in affiliation with the International Organization for Biological Control of Noxious Animals and Plants (IOBC). This Working Group was formally established in 1993 at the 3rd International Workshop, held in Abidjan, Côte d’Ivoire. The workshops have been held in Asia (Thailand, Indonesia, India and Taiwan), Africa (Côte d’Ivoire, South Africa) and Australia.
The Chromolaena odorata Newsletter was launched during the 1st Workshop, in order to publish short articles and news on biocontrol and management of the weed. A proceedings of each of the seven workshops held thus far has been published. Each of the workshops ended with the promulgation of a set of recommendations.
Dr R. Muniappan of the University of Guam has been instrumental in organizing the workshops and forming the working group, of which he was convenor until 2006. At the 7th workshop in Taiwan Dr C. Zachariades (Agricultural Research Council, South Africa) took over as convenor for a 5-year period.
The workshops, proceedings, newsletters and working group have all proved very useful in the exchange of information and insects, in addressing regional problems such as the conflict of interest on the status of chromolaena in West Africa, and in giving direction to further research.
The workshop in Australia in 2003 was broadened to include other invasive chromolaena species, and a recommendation was made to broaden the focus of the working group to other invasive Eupatorieae. Consequently, the 2007 Taiwan workshop included both chromolaena and Mikania micrantha.
Reference:Boller, E.F., J.C. van Lenteren and V. Delucchi (eds.) 2006. International Organization for Biological Control of Noxious Animals and Plants: History of the first 50 Years (1956-2006). IOBC, Zurich, Switzerland. 275 pp.
1.1 The Secretariat be established and located in Guam for the
present, and to produce a "Chromolaena odorata Newsletter".
1.2 An International Working Group on Biological Control of
Chromolaena odorata be formally established and seek an affiliation
with the International Organization for Biological Control (IOBC).
1.3 Countries and organizations active or planning to initiate
biological control of C. odorata programs should inform the Secretariat
or the working group to disseminate the information and to maximize cooperation
1.4 To encourage exchange of natural enemies of C.
odorata in conformity with the local or regional regulations, the
researchers must document all relevant information pertaining to identity,
origin, numbers received, numbers released, locations and dates of releases
together with pre-release and post-release evaluation of the natural enemies
1.5 Various donor agencies be encouraged to support activities
that will strengthen biological control of C. odorata.
1.6 In the light of the benefits derived from this workshop, it
will be more useful to organize another one in the next two or three years to
follow up current activities and to review the progress made as well as to
formulate future action plans.
2.1 In view of the need for exchange of information and the
coordination of research activities, a network on biological control and
management of C. odorata should be established
immediately with an international coordinating secretariat at the University of
Guam and assisted by four regional coordinators.
2.2 Given the inefficiency and high cost of other control
techniques and recognizing the success of biological control of C.
odorata in Guam and neighboring islands, it is recommended that countries
with a C. odorata problem should initiate biological control programmes
starting with importation of P. pseudoinsulata.
2.3 Recognizing the potential of other biological control
agents, further exploration and screening should be conducted in the natural
range (Central and South America) of C. odorata.
2.4 In tandem with efforts on biological control of C.
odorata, research on the ecology of C. odorata should be conducted
to evaluate its impact in Western and Central Africa, taking cognizance of
similar studies prior to the arrival of the weed into the region.
2.5 Recognizing that there are significant gaps in our
knowledge of the weed and its biological control agents, there is a need to
pursue basic research not only into their ecology but also into their biology
2.6 Appreciating the safety and sustainability of biological
control, it is strongly recommended that donors support research and
implementation of biological control of C. odorata in countries
affected by the weed.
2.7 A third Intemational Workshop on Biological Control and
Management of C. odorata should be held in 1993. In order to sensitize,
focus and promote further work in Africa, it is recommended that it be organized
in West Africa in collaboration with the Food and Agriculture Organization of
the United Nations (FAO) Regional Office of Africa.
3.1 The Workshop foresees the continued spread of C.
odorata in sub-Saharan Africa, and recommends:i) that this spread be
monitored by the countries concerned, andii) that countries where C.
odorata has not been reported be informed of the likely arrival of C.
odorata, and be provided with balanced information on the potential
ecological and socio-economic impacts of the weed.
3.2 The Workshop recognizes that, of the major land systems in
the humid and sub-humid tropics of Africa:i) the arid savanna zone is not
susceptible to invasion by C. odorata;ii) dense evergreen forests
in the humid tropical zone are not susceptible to invasion when intact, but
become very susceptible whenever disturbed;iii) the moist savanna zone is
very vulnerable to invasion;iv) the native flora in the vulnerable ecologies
is likely to be dominated and eventually suppressed by C. odorata,
affecting the entire biodiversity. The Workshop also encourages the
collection and synthesis of research in the management of C. odorata
within these vulnerable ecologies.
3.3 The Workshop strongly recommends that where biological
control of C. odorata is found necessary in Africa and elsewhere, it
should be conducted according to the FAO Code for the Importation and Release of
Biocontrol Agents. In particular, Article 3 which stipulates that importation
can be made only with governmental consent from the importing country, that
other countries in the region concerned be consulted, and that introductions
should only be made when it is in the best interest of the public. Article 4
which stipulates that the host range of any potential agents must be adequately
investigated before release should also be followed.Since conflicts of
interest are likely to occur, the Workshop also recommends that the different
viewpoints and arguments expressed in the Proceedings of this Workshop be
considered before any permits to import are issued.
3.4 The Workshop encourages African countries as well as
international research agencies to initiate comprehensive research on the status
of C. odorata, on its importance in the various agro-ecosystems, and on
its impacts on native flora and fauna. The Workshop also encourages African
countries to organize national meetings to document available information on the
status of C. odorata, and its economic importance in the
agro-ecosystems of each country.
4.1 So far, only Pareuchaetes pseudoinsulata has been
used for biological control of C. odorata in many countries.
Importation of other effective natural enemies such as Procecidochares
connexa, Mescinia parvula, Melanagromyza eupatoriella, Actinote anteas,
etc., should be considered.
4.2 Countries wherein Pareuchaetes pseudoinsulata has
been introduced should consider introduction and establishment of
Procecidochares connexa from IOPRI in Indonesia. Host specificity
testing of this natural enemy has been carried out in Indonesia and the
information on host plants tested is available.
4.3 The Workshop highlights the importance of the complex of
alien invasive weeds, including Chromolaena odorata, in the Western
Ghats, and other ecologically important regions in the humid tropics which are
threatening biodiversity of these regions; this should be brought to the
attention of the Indian and other governments and international donors in order
to seek support and funding for multi-disciplinary programmes of management of
4.4 National governments should promote collaborative
programmes nationally and internationally on management of Chromolaena
odorata, Parthenium hysterophorus, Mikania micrantha, Lantana camara, Ageratina
adenophora and other alien invasive weeds.
4.5 National governments through their agricultural research
agencies should include use of pathogens in biological and integrated control
programmes against noxious weeds.
4.6 For immediate suppression of C. odorata in certain
conditions, where alternative technology is not available, research on herbicide
and other methods should be encouraged.
4.7 Alternative uses of Chromolaena, such as use as a green
manure crop, in certain agro-ecological systems should be explored.
4.8 It is recommended that a national network should be
formulated to co-ordinate the research programmes on Chromolaena
odorata in India.
4.9 Training programmes on biological control of exotic weeds
at national, regional and international levels should be encouraged.
4.10 In view of the serious problems caused by C.
odorata in developing countries in Asia and Africa to the livelihood of
small- and medium-scale farmers, and the threat to biodiversity in natural
ecosystems, countries of origin of the plant (tropical Americas from Argentina
to the USA) are requested to assist researchers from affected countries and
their agencies by allowing exploration for, and collection and export of
promising candidate organisms for biological control of the weed, without
imposing administrative and other barriers to the export of live materials.
5.1 To change the name of the future workshops to
‘International Workshop on Biological Control and Management of
5.2 To adopt as the common name ‘chromolaena’ in future
literature for Chromolaena odorata.
5.3 That other specialist tephritid taxonomists be approached
to sort out the generic placement of (Pro) Cecidochares connexa
Macquart and its relationship to Procecidochares alani and P.
5.4 Cooperative international work should be encouraged
especially in the aspects of foreign exploration and preliminary screening of
5.5 As a follow-up to the 1993 recommendations of the
Chromolaena odorata workshop held in Abidjan, West and Central African
stakeholders should hold a regional meeting in 2001 to assess the expansion of
the biological control effort across the region. The recommendations of this
meeting will be tabled to the regional governments.
5.6 That an integrated weed management strategy including
eradication where applicable (countries where the weed has only been found),
slashing, burning, cultural, chemical and biological control be developed for
the management of C. odorata.
6.1 Governments of West and Central Africa should introduce
6.2 Regional organizations e.g. SPC to produce public awareness
material on chromolaena for identification and containment and control
6.3 All information produced by countries and organizations on
chromolaena be linked to the chromolaena website at UQ.
6.4 Expand the focus of the workshop to include other invasive
Eupatorieae (e.g. Ageratina, Ageratum, Austroeupatorium, Campuloclinium,
6.5 Research to assess additional natural enemies, including
fungi, should be encouraged in countries having problems with invasive
6.6 Eradication of chromolaena, wherever possible, should be
the preferred strategy, and continuation with eradication efforts in Australia
and the Marshall Islands must be given the highest priority.
6.7 An e-mail list for invasive Eupatorieae should be set up
and maintained by Wayne Parasram.
7.1 Governments of all countries affected by chromolaena are encouraged to
consider the introduction of Cecidochares connexa.
7.2 Governments of all countries affected by chromolaena and
mikania are encouraged to send representatives to the next workshop.
7.3 Regional organizations e.g. SPC and countries affected to
produce public awareness material on chromolaena for identification and
containment and control measures.
7.4 Countries should increase awareness of, and promote,
biological control of weeds and its benefits.
The IOBC Working Group will for now remain
officially a working group only on Chromolaena odorata, but will
involve itself in biocontrol and management of other invasive alien Eupatorieae
as considered desirable and necessary. The Chromolaena odorata
Newsletter will remain as is for now. However, workshops will continue to
accommodate other tropical and subtropical Eupatorieae as the need arises, and
this website provides links and some information on these weeds.
Prospects for the biocontrol of chromolaena have improved
dramatically since the 1990s. Pareuchaetes species have been
established in several more countries, and although the performance of these
moths has not always been adequate, they have had a positive impact.
Actinote thalia pyrrha has been established in Indonesia, and attacks
not only C. odorata but also the invasive Eupatorieae M.
micrantha and A. inulifolium. C. eupatorivora has established in
South Africa and may be having an impact. Undoubtedly the most successful agent,
however, has been C. connexa, which has had a real and consistent
impact in most of the areas where it has been released for long enough to build
up in population. Several other very promising agents will become available from
the SA program within the coming years. The Working Group will therefore
continue to work to increase awareness of the threat of chromolaena and
biocontrol solutions to it, to facilitate the exchange of information, to make
available suitable insect and pathogen agents for release (particularly at this
stage, C. connexa), and to identify areas of need for further research
With regards to M. micrantha, the rust fungus
Puccinia spegazzini has been released in India, China and PNG. In India
it initially spread from the release sites but may not have persisted; in China
it spread but further assessments are not available; in PNG it is spreading (C.
Ellison, unpubl. data). Releases are planned in Fiji. The Working Group will
thus also promote the use of this agent where appropriate.
Proceedings of the First International Workshop on
Biological Control of Chromolaena odorata, 29 February – 4 March 1988,
Bangkok, Thailand. Muniappan, R. (ed). Agricultural Experiment Station,
University of Guam, Mangilao, Guam, 1988.
Proceedings of the Second International Workshop on Biological
Control of Chromolaena odorata, 4-8 February 1991, Bogor, Indonesia.
Muniappan, R. and Ferrar, P. (eds). ORSTOM & SEAMEO BIOTROP, Bogor, BIOTROP
Special Publication No. 44, 1991.
Proceedings of the Third International Workshop on Biological
Control and Management of Chromolaena odorata, 15-19 November 1993.
Prasad, U.K., Muniappan, R., Ferrar, P., Aeschliman, J.P. and de Foresta, H.
(eds). Agricultural Experiment Station, University of Guam, Mangilao, Guam,
Publication No. 202, 1996.
Proceedings of the Fourth International Workshop on Biological
Control and Management of Chromolaena odorata, 14-18 October 1996,
Bangalore, India. Ferrar, P., Muniappan, R. and Jayanth, K.P. (eds).
Agricultural Experiment Station, University of Guam, Mangilao, Guam, Publication
No. 216, 1998.
Proceedings of the Fifth
International Workshop on Biological Control and Management of Chromolaena
odorata, 23-25 October 2000, Durban, South Africa. Zachariades, C.,
Muniappan, R. and Strathie, L.W. (eds). ARC-PPRI, Pretoria, South Africa,
of the Sixth International Workshop on Biological Control and Management of
Chromolaena, 6-9 May 2003, Cairns, Australia. Day, M.D. and McFadyen, R.E.C.
(eds). ACIAR, Canberra, Australia, ACIAR Technical Reports 55, 2004. [Proceedingsofthe6thWorkshopAustralia2003.pdf]
of the Seventh International Workshop on Biological Control and Management of
Chromolaena odorata and Mikania micrantha, September 12 - 15
2006, Pingtung, Taiwan. Lai, P-Y., Reddy, G.V.P. and Muniappan, R. (eds).
National Pingtung University of Science and Technology, Pingtung, Taiwan,