Invasive plant pathogens threatening the USA
Invasive plant pathogens represent a threat to US agriculture, forestry and the environment. Accurate information on these pathogens is required to help prevent their introduction and spread. The Plant Pathogens Subcommittee of the US Federal Interagency Committee on Invasive Terrestrial Animals and Pathogens (ITAP) has identified the worst plant pathogen threats to the USA. CABI is commissioning the compilation of data on these plant pathogens to be published as full datasheets in the Invasive Species Compendium [www.cabi.org/isc] (an open access global resource currently containing over 10,000 datasheets).
Biological control of apple leaf-curling midge in Canada
A European biological control agent may help control an exotic pest of apple trees in western Canada. Damage from the apple leaf-curling midge in eastern Canada was effectively reduced by introducing a European natural enemy, Platygaster demades, in the 1990s. The pest arrived in British Columbia more recently, where releases of P. demades are now being considered. First, however, the identity of P. demades needs to be confirmed with molecular tools and its host range defined.
Biological control of hawkweeds
European hawkweeds are invasive in North American pastures, where mechanical methods of control are difficult and ineffective. Chemical control with broad-spectrum herbicides is not selective and relatively expensive, with the weed often recolonising untreated pastures. Insects that feed on hawkweeds in Europe have been studied as potential biological control agents for North America since 2000. Two agents have been released in Canada – the gall wasp Aulacidea subterminalis in 2011 and the hoverfly Cheilosia urbana in 2017.
Revisiting biological control of field bindweed
Field bindweed is a Eurasian vine whose dense creeping and twining growth smothers other vegetation and its long-lived seeds and deep roots make it hard to control. It is a noxious weed of agricultural fields in temperate regions and has become invasive in North America. CABI is studying sustainable control methods using host-specific natural enemies, which could be introduced into North America as biological control agents.
Biological control of garlic mustard
Crushed garlic mustard leaves and seeds smell like cultivated garlic and have been used as flavouring in cooking for centuries. Garlic mustard is a brassica from Eurasia that was accidentally taken to North America and became invasive in many of its forests. Together with partners, CABI is exploring the possibility of using specially selected and tested insects from the native range in order to safely control the plants spread and impact in the introduced range.