Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Host specificity and environmental impact of the weevil Hylobius transversovittatus a biological control agent of purple loosestrife (Lythrum salicaria).

Abstract

The introduction of L. salicaria into N. America and its spread into wetlands has led to the degradation of these important habitats for wildlife. A classical biological control programme for reducing the numbers of this invasive plant and improving regeneration of the native flora and fauna is discussed. Field trials in Lower Saxony, Germany, during 1990, demonstrated that H. transversovittatus is highly host-specific to the target weed. It was suggested that attack of 2 test plant species (L. alatum and Decodon verticillatus) during host range screening was most likely due to artificial laboratory test conditions. An environmental assessment of the potential effects of releasing H. transversovittatus in N. America indicated that benefits outweighed any potential negative impact. Therefore its field release was approved in 1992.