Two biological control agents maintain the potential to be effective agents against bugweed, after the incorporation of plant ecophysiology and climatic modelling in the assessment of their effectiveness.
A mealybug (Delottococcus aberiae De Lotto) of southern African origin has recently been noticed in Spain where it causes severe distortions on young citrus fruit. Since the local natural enemies are ineffective in controlling the mealybug, and farmers rely on chemicals to protect their fruit.
The water fern (Salvinia molesta) is an aggressive invader of freshwater systems where it affects the services that these ecosystems deliver. Fortunately, the use of a natural enemy of the water fern (a biological control agent), the weevil (Cyrtobagous salviniae) has been highly successful in many countries, including South Africa where the water fern is no longer considered to be problematic.
Invasive plants compete with native plants for important resources like water and nutrients, often outcompeting or even causing local extinction of indigenous plants. Australian acacias are one such group of plants in South Africa...