Some studies on the biological control of Chromolaena odorata (Eupatorium odoratum)

Abstract

Laboratory studies on the biology and life cycle of the deforliator insect Ammalo insulata walk. (Lep. Arctiidae), introduce to Sri Lanka to control the pernicious weed Chromolaena odorata Robinson, indicated that the insect could complete the life cycle on the two known hosts, C. odorata and Ageratum conyzoides but preffered C. odorata Fluctuations on the deforliator insect population in a locality were monitored while periodc increases of the insect coinciding with new generations were noted. Larval and pupal mortality appear to be major constraint in the successful establishment of the insect. The larval population was also low during the dry season. Some changes inthe insect population in relation to host and climatic factors have been noted.