Distribution and biological control of Chromolaena odorata
Invasive Plants: Ecological and Agricultural Aspects
Chromolaena odorata, a neotropical plant, has spread throughout humid tropical Asia, Africa, the Western Pacific and a small area in northern Australia. A Commonwealth Institute of Biological Control project in 1966 identified over 200 arthropod natural enemies of this weed. Pareuchaetes pseudoinsulata was one of the first natural enemies identified in this project. It was introduced to Ghana, Nigeria, India, Sri Lanka and Malaysia in the 1970s and early 1980s, but it established only in Sri
... shed only in Sri Lanka. In the mid l980s it was confirmed that P. pseudoinsulata had established in Malaysia from the earlier introductions and had fortuitously spread to Brunei and the Philippines. Introductions after the mid 1980s resulted in its establishment in Guam, Rota, Tinian, Saipan, Yap, Pohnpei, Kosrae, India, Indonesia and Ghana. Establishment did not occur following releases in Thailand and Ivory Coast. The success rate of P. pseudoinsulata establishment has increased from 17% in the 1970s and early 1980s to 75% from the mid -1980s onwards. The seed-feeding weevil, Apion brunneonigrum failed to establish after being released in Ghana, Nigeria, Malaysia, India, Sri Lanka and Guam. The eriophyid mite, Acalius adoratus has fortuitously established in South and Southeast Asia. The gall fly has established in Indonesia. It is possible that the C. odorata in South Africa is a different biotype from those in Asia, the Western Pacific and the rest of Africa. The natural enemies established in the Old World could not be established in South Africa.