A new invasive pest of particular concern to Switzerland’s orchard industry is the Comstock mealybug, Pseudococcus comstocki. Originating from Asia, the Comstock mealybug was first detected in 2016 in fruit crops of the Swiss canton of Valais. Following its detection, the mealybug has caused significant local economic damage to apricot, pear and apple production, especially during 2018 and 2019. Chemical control is one way of helping to fight the pest but it has produced mixed, and often, insufficient results. Biological control is another method and this project, therefore, aims to develop a sustainable and environmentally friendly, biological control method for the Comstock mealybug.
Invasive non-native species are a major threat on oceanic islands due to their vulnerability and endemism, typical of island ecosystems. On Tristan da Cunha, a remote group of islands in the South Atlantic, Brown soft scale, (Coccus hesperidum), an invasive alien scale insect, has infested Tristan’s only native tree, Phylica arborea; and is now threatening the extinction of one of Britain’s rarest bird species, Nesospiza buntings. There is, therefore, an urgent need to find an appropriate method to mitigate the impact of the scale insects and prevent the total collapse of the Phylica forest. The aim of this project is to select and safely test suitable biocontrol agents to reduce scale numbers below a damaging threshold and safeguard Tristan’s endemic buntings.