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An old problem revisited: biological control of toadflaxes

Native to Europe, toadflaxes were introduced to the USA and Canada over 100 years ago as ornamental plants. They now occur over much of temperate North America and are declared noxious in eight US states. CABI identifies specific natural enemies that can be introduced into North America as biological control agents to reduce the vigour, density and spread of this invasive plant.

Tackling common tansy in North America

Common tansy is an aromatic Eurasian plant species with a long history of use as a medicinal herb. Introduced for this purpose to North America, it has since become invasive. One reason for this could be the absence of the natural enemies that keep it in check in its area of origin. CABI has been tasked with identifying specialist natural enemies from Eurasia that can be introduced into North America as biological control agents.

Biological control of diamondback moth in Canada

The diamondback moth is a global pest. Canadian farmers often have use chemicals to protect their crops. This is costly and the pest is becoming immune, meaning additional control options are needed. In Europe, Asia and Africa, Diadromus collaris, is a major parasitoid of the moth. It has been introduced to several countries or regions and has established as a successful biocontrol. CABI is therefore carrying out life table studies in Europe to determine if its introduction is a viable strategy.

Controlling noxious Russian knapweed in North America

Russian knapweed is one of several invasive plants of rangelands that arrived in North America as a seed contaminant in the 19th century, in this case from Asia. Biological control is often a good approach for these plants, but a nematode species introduced in the 1970s proved ineffective against Russian knapweed. Funded by a US and Canadian consortium, CABI has been tasked with researching new biological control agents for introduction, some of which are already showing promise.

Protecting leeks and onions from pests

The invasive leek moth poses a significant and immediate threat to producers of leeks, onions, garlic and chives in North America. The larvae mine the green tissues, reducing the marketability of crops. The pest’s distribution is expanding, with no signs of suppression by indigenous natural enemies. We are supporting an integrated pest management (IPM) programme run by Agriculture and Agri-Food Canada to combat the leek moth using specialized natural enemies from its area of origin.