Battling the Chromolaena weed
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CTA. 2005. Battling the Chromolaena weed. Spore 117. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/47941
Internet URL: http://spore.cta.int/images/stories/pdf/old/spore117.pdf
The National Agricultural Research Institute (NARI) has declared war on the Chromolaena weed (Chromolaena odorata) in Papua New Guinea (PNG), and has won the first battle. Chromolaena is one of the most serious invasive weeds in the tropics
The National Agricultural Research Institute (NARI) has declared war on the Chromolaena weed (Chromolaena odorata) in Papua New Guinea (PNG), and has won the first battle. Chromolaena is one of the most serious invasive weeds in the tropics. As well as having a highly damaging effect on agriculture, the weed is also a major threat to biodiversity. Chromolaena has been spreading since it was first sighted in the Gazelle Peninsula in East New Britain in the 1960s and is currently confirmed in 12 provinces of PNG. Now NARI, which has been conducting research into the biological control of this weed since 1999, has found two natural enemies of the alien species. Two insects have been released for biological control, the moth Pareuchaetes pseudoinsulata and the gall fly Cecidochares connexa. The larvae of the moth feed on Chromolaena leaves and, when there are sufficient quantities of them, they cause heavy defoliation, resulting in the destruction of the weed. Adults of the gall fly lay eggs in soft apical stem tissue and the larvae, upon hatching, feed in the stem, causing gall formation. The galls affect the flow of water and nutrients to other parts of the weed, thus stunting plant growth and reducing seed production. In the Markham Valley of Morobe Province, the combined effect of the moth and the gall fly has produced spectacular defoliation and the death of many plants in areas of previously impenetrable Chromolaena weed. NARI is rearing and releasing more moth larvae and gallflies, which can be supplied for release when new infestations of Chromolaena weed are detected. NARI Weeds Programme PO Box 1639 Lae Papua New Guinea Fax: +475 1071 E-mail : email@example.com