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Parrot's Feather

A popular aquatic garden plant that spreads with water currents, animals, boats/trailers and fishing gear. Dense stands can stagnate water, and increase breeding grounds for mosquitoes learn more »

Zebra/Quagga Mussels

These tiny freshwater mussels clog drains, damage infrastructure, and are very costly to control/eradicate learn more »

Giant Hogweed

A towering toxic invasive plant with WorkSafe BC regulations learn more »

European Fire Ant

A tiny ant with a toxic sting learn more »

Purple Loosestrife

An aggressive wetland invader that threatens plant and animal diversity learn more »

Orange Hawkweed

Also yellow, these invasive plants replace native vegetation along roadsides, and threaten areas not yet reforested learn more »

Japanese Knotweed

Grows aggressively through concrete, impacting roads and house foundations learn more »

Spotted Knapweed

A single plant spreads rapidly with up to 140,000 seeds per square metre learn more »

Scotch Broom

An evergreen shrub that invades rangelands, replaces forage plants, causes allergies in people, and is a serious competitor to conifer seedlings learn more »

Agriculture Canada releases moth to eat invasive ‘dog-strangling vine’

NOVEL HELP IN THE FIGHT AGAINST INVASIVES:  ONTARIO RECEIVING NEW BIOCONTROL AGENT AGAINST DOG-STRANGLING VINE

The invasive weed, dog-strangling vine may have met its match. Researchers from Agriculture and Agri-Food Canada (AAFC), University of Toronto, Carleton University (CU), the University of Rhode Island (URI), Commonwealth Agricultural Bureaux International (CABI), and the forest management company Silv-Econ Ltd are investigating a new biological control agent with potential for managing dog strangling vine, the caterpillar Hypena opulenta.

Dog-strangling vine (DSV Vincetoxicum rossicum), also known as swallowwort, is thought to have been brought to North America from the Ukraine in the 1800’s. Since then, populations of DSV have become established through much of southern Ontario and the plant is increasingly becoming an ecological threat. With no native herbivores to feed on it, the plant spreads rapidly and outcompetes native species forming dense monocultures in forests and open areas. In contrast, in its native range in Europe, swallow-worts are scarce. Dog-strangling vine is also a threat to the monarch butterfly because while the monarchs will lay eggs on the weed, the monarch caterpillars cannot eat the plant and are lost.

The insect, Hypena opulenta, was first identified by URI and CABI researchers as a potential biological management tool in 2006. Since then, it has undergone extensive host-range testing and it was determined that the caterpillar can only survive on DSV, had a significant impact on DSV biomass in cage trials and poses no risk to native plants. Following testing, AAFC scientists petitioned for a release permit for the caterpillar, and it was approved for release in Canada in late 2013.

To date the results are encouraging, Hypena caterpillars released by AAFC and Carleton University in the Ottawa area in 2014, overwintered successfully in field cages during the 2014-2015 winter. From both this release, and a subsequent open release in 2015, there has been a confirmed second generation of larvae, meaning that Hypena is reproducing in situ. Defoliation of DSV at release points is easily detectable and entire DSV plants are yellowing in response to insect feeding on just a few leaves. Adult moths and larvae were also recorded spreading from up to 100m from the release sites. The research team is continuing to monitor these initial release locations for additional impact on the DSV plants, spread of the insects and successful overwintering.  These “nurse”  sites and additional studies examining methods to mass-produce the insects will form the basis of a larger release program planned for throughout Ontario.

Successful biological control is a long-term project. Dog strangling vine has a head-start of 100 years or more and it will take several years before caterpillar populations establish and increase enough to see wide-scale impacts on the plant. The goal is that Hypena will eventually help to restore an ecological balance between DSV and other native plants, which will assist in the restoration of invaded habitats.

For more information about Hypena research, please contact:

Hypena Spokesperson

Dr. Rob Bourchier
Research Scientist

Lethbridge Research and Development Centre
Agriculture and Agri-Food Canada

403 317-2298
Robert.Bourchier[at]agr.gc.ca