Not so sweet after all: are candy-striped spiders a threat to ecosystems across North America?

New study offers insight into the behavior of spiders who prey on sleeping pollinating insects
Published: 19 April 2023
For years, pollinator declines have been a pressing issue for ecosystem health and food security in the face of climate change and human impacts on the environment. Even in their sleep, pollinating insects cannot catch a break – for fear they’ll be taken down by a small, but mighty predator: the candy-striped spider. Research published in Ecology took a closer look into this spider’s behaviour and found that the result of their stealth attacks could have substantial impacts on ecosystems.

Most likely accidentally introduced to both the East and West Coasts a little over a century ago, the candy-striped spider is a very common spider in North America. The spider's striking colour varieties have attracted much research into their genetics, but before now very little was known about their behaviour.

“This common spider previously flew under the radar of researchers in North America and almost nothing was known about its diet and behavior”, explains Catherine Scott, a Postdoctoral Fellow in McGill’s Department of Natural Resource Sciences and co-author of the study. “We documented their diet and predation behaviour in the field and learned that they use a variety of tactics to take down prey much larger than themselves, including sleeping bees and wasps.”

While these spiders may have negative effects on pollinators, they may have positive effects of preying on insects that are pests of agricultural crops. In terms of next steps, the researchers will investigate candy-striped spiders in food webs of agro-ecosystems in southern Quebec. “At a time where the world is facing a biodiversity crisis that includes unprecedented declines of insect pollinators, future studies will help determine whether their benefits as natural pest-controllers outweigh their negative impacts as predators of pollinators “says Scott.

About the study

They mostly come at night: Predation on sleeping insects by introduced candy-striped spiders in North America” by Catherine E. Scott and Sean McCann was published in Ecology.

About McGill University

Founded in Montreal, Quebec, in 1821, McGill University is Canada’s top ranked medical doctoral university. McGill is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning three campuses, 11 faculties, 13 professional schools, 300 programs of study and over 39,000 students, including more than 10,400 graduate students. McGill attracts students from over 150 countries around the world, its 12,000 international students making up 30% of the student body. Over half of McGill students claim a first language other than English, including approximately 20% of our students who say French is their mother tongue.

Back to top