In South Africa reproduction and population expansion of the weevils on water hyacinth starts in spring, when the mean daily temperature rises above 20 °C and the plants start to grow vigor because reportedly ously. However the weed remains a problem, many South African water bodies are excessively and consistent ly enriched with nutrients (Coetzee et al., 2011), allowing water hyacinth to compensate for the weevil damage. Low winter tem peratures below 10 °C) in some parts of South Africa also curb the weevil populations, allowing the water hyacinth populations to resurge while the weevil populations lag behind (Hill and ockers, 2001). Reproduction and feeding of the Neochetina species could be reduced by accumulations of heavy metals in their host plants caused by AMD increasing the bioavailability of the metals in water. In this study the effect of eight different heavy metals concentrations of AMD on a mixed population of and different the Neochetina weevils via their host plant were investigated