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The northern black widow spider is now established in Québec

The results of a new study conducted by researcher Maxime Larrivée of the Montréal Space for Life Insectarium and his colleagues at McGill University and Université du Québec à Rimouski, demonstrate, with supporting evidence, that southern Québec up to Lake Saint-Pierre is now part of the ecological niche of the northern black widow spider (Latrodectus variolus).

Citizen science at work

The emergence of Web 2.0 contributed to the birth of citizen science and consequently to the remarkable increase in the quantity of information available for establishing the historical and current distributions of less charismatic and often less studied species – what researchers call “dark biodiversity.”

In effect, it was in integrating the data of citizen scientists with museum data by way of advanced modeling techniques that scientists were able to pool enough information to illuminate the northward evolution of the northern black widow’s ecological niche.

Their predictions moreover were validated by the recent discovery of the spider in the wild in three different places in southern Québec and in Ottawa very close to the border.

A threatened mygalomorph species (Sphodros niger – the black purse-web spider) also featured in the study. Yet although this particular spider, the size of a dollar coin, has been observed as far up as Belleville, Ontario, it still hasn’t been spotted in Québec, even though its habitat requirements may be present here now.

Should we worry about the presence of this widow of dubious reputation?

All black widow species trigger the collective imagination. But unlike the black-legged tick, which comprises a public-health issue, our northern black widow avoids humans, who represent a danger for it.

Citizens therefore have no grounds for worry, bites from this species being extremely rare, and when they do happen the amount of venom injected is minimal.

How do we identify the northern black widow and where do we find it?

It hides under old stumps, in cavities of all kinds and in recesses of buildings, provided these are secluded, dark places.

On its abdomen it displays an incomplete hourglass pattern cut off in the middle and it has a series of red dots and sometimes pale lines on the dorsal portion. Its web is irregular, and the spider hangs upside down from it.

To consult the detailed results of the study (English only), click here :

Care to become a citizen researcher and take part in this study?

To learn how to go about it and how to share your observations, consult our website on the northern black widow monitoring project at this address:

Nature dwells within us In 2018, Space for Life is looking at the many ways of dwelling on our planet. It’s a source of inspiration for some, and a call to reflection and dialogue for others, leading to citizen-based initiatives. This year at Space for Life, nature dwells within us more than ever!

About Space for Life

Montréal Space for Life is made up of four attractions on the same site: the Jardin botanique, Biodôme, Insectarium and Planétarium Rio Tinto Alcan. These four prestigious Ville de Montréal institutions form Canada’s most important natural science museum complex. Together, they’re launching a daring, creative urban movement, urging everyone to rethink the connection between humankind and nature and to cultivate a new way of living.

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Montréal, August 8, 2018

Information Interview requests:

Nadine Fortin, Communications coordinator

Montréal Space For Life

514 868-3053


Find out more..

To find out more about this research and the work of Yifu Wang and the co-authors, keep up-to-date with the second issue of the digital magazine which features a Q and A interview with Yifu Wang. To be sent the second issue for free, you can subscribe for free here.


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