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Wild pollinators and plants evolved to rely on each other could face uncertain future

Wild pollinators and plants evolved to rely on each other could face uncertain future

Home » Category Listing » Wild pollinators and plants evolved to rely on each other could face uncertain future

Wild pollinators and plants evolved to rely on each other could face uncertain future

Ů of the Indigenous three sisters gardens and their most important wild bee pollinators by York University bee experts an important first step

TORONTO, May 22, 2024 – The loss of even one wild bee species can disrupt the reproductive success of certain plants resulting in fewer vegetables, fruits and flowers, say York University researchers who studied how pollinators and plants rely on each other, specifically in Indigenous gardens in the Great Lakes Region.

Bumble bee on patty pan squash. Photo by Shelby Gibson

Pollination deficits can threaten global food security. A decline in the bounty of plants can in turn lead to fewer resources for pollinators and put their survival at increased danger. Researchers at York University delved into its significance using a three sisters garden, along with additional culturally significant plants to see what was abuzz.

“This delicately balanced pollinator-plant network is at risk of future human-caused collapse, but it has not been well studied and there has been little understanding of how this co-reliance works and the threats against it,” says York University PhD Candidate Shelby Gibson of the Faculty of Science in the of co-author York University Associate Professor of the Faculty of Environmental and Urban Change (EUC).

Additional co-authors include , a York PhD Faculty of Science graduate now of the Canadian Museum of Nature, and Associate Professor of EUC.

The three sisters garden uses an ancestral Indigenous growing method, a form of intercropping that involves the growth of multiple crops simultaneously, including culturally important medicinal plants. However, land use changes, the use of pesticides and other agricultural practices, the invasion of non-native species and climate change are increasingly impacting how pollinators and plants match up.

The study, , published today in the journal PeerJ, looked at how the pollinator community visiting the garden differed from the surrounding wild pollinator community.

“Knowing what is involved with these pollinator-plant networks can help us minimize future disruptions that could result in the loss of both plants and wild bee species,” says Colla. “It can also provide us with baseline information about the role of wild bees and the stability of the network to weather environmental change.”

A three sisters garden. Photo by Shelby Gibson

This delicately balanced pollinator-plant network is at risk of future human-caused collapse, but it has not been well studied and there has been little understanding of how this co-reliance works and the threats against it.

Shelby Gibson

The three sisters garden has corn, common bean and squash, which rely on insect pollination. For squash, the pollination window is short – their flowers open at dawn and close by noon – and it is historically pollinated by the hoary squash bee.

Hoary squash bee on patty pan squash. Photo by Shelby Gibson

Overall, some 37 species or 59 per cent of the about 63 bee species thought to occur in the wider community were identified in the garden. Bumblebees were the most frequent genus with the most frequent species being the common eastern bumble bee. Equally as common as the common eastern bumble bee, was the hoary squash bee. These bees interacted mostly with Patty Pan squash. The hoary squash bee is recognized as a key species for the three sisters garden and an important pollinator to protect. They have specialized hairs for collecting squash pollen and are extremely active during the squash pollination window.

Although the range of the hoary squash bee has grown, it doesn’t typically include wild squash and its range has been impacted by continued agricultural expansion. In their absence, honey bees and bumble bees are known to be able to pollinate squash, but it is the aptly named hoary squash bee that has co-evolved with the plant.

Recommendations for management of the hoary squash bee within the agroecosystem are to minimize pesticide exposure, provide nesting sites (they are ground nesters), maintain field proximity, monitor populations, parasites, and pathogens, and limit deep tillage of the earth. Many of the things already in practice at the three sister garden.

The researchers say further research is necessary to ascertain how to manage ongoing threats to the common eastern bumble bee and the hoary squash bee, both important pollinators in the three sisters garden system, but also the overall critical role of wild pollinators for culturally significant plants. This could include the role of policies and programs that support and promote conservation and pollinator-plant diversity.

About York University

York University is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for success. York's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. York’s campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contact: Sandra McLean, York University Media Relations, 416-272-6317, sandramc@yorku.ca