Part 2: How research about pesticide risks informs our efforts to rewild agricultural landscapes

Part 2 of 2

One of the most rewarding aspects of my work has been returning to places where I helped design pollinator habitat. It is incredibly satisfying to witness the transformation of mowed lawn or marginal areas filled with invasive or other non-native plants into thriving, valuable ecosystems that support the hum of bees, butterflies and other beneficial insects. This rewilding of the landscape is a significant part of the Xerces conservation mission.

Last week, I shared a review of the latest research on how agricultural pesticides may impact nearby pollinator habitat. Today, I’ll talk about how we apply this research to our work at Xerces.

Over the past decade, Xerces has worked with thousands of farmers and land managers to build over a million acres of habitat. Each of these projects, no matter how small, is meaningful and important to us. Our staff spend hours on the details, fine-tuning the mix of plants to suit the local conditions and support as many species as possible, determining how the site will be prepared and installed, and finding ways to protect the resulting habitat from pesticides.

We strive to create the highest quality habitat possible each time we are given the opportunity to expand biodiversity and help working lands come alive with the buzzing of insects.
 

Catchment habitat designed to capture nutrient and sediment runoff, like this flowering prairie strip at Neal Smith Wildlife Refuge in Iowa, may be more ubiquitously contaminated with pesticides used in nearby crop fields than other types of habitat in agricultural landscapes. Photo: Lynn Betts, NRCS/SWCS (Flickr)
 

How Xerces incorporates science into our conservation actions

Let’s review the key takeaways from our dive into recent research on the risks of pesticide contamination of pollinator habitat, this time from the lens of our conservation work:

1. Flowering habitat that provides food and shelter for pollinators is critical for sustaining populations of these insects in all landscapes.

2. Pesticide contamination reduces the quality and value of habitat, as pesticide exposure can reduce insect survival and reproduction.

3. Xerces will always encourage actions to reduce pesticide risk, as reducing pesticide use and mitigating risks will improve the quality of habitat and the ability of insects to survive and thrive.

4. With limited resources, we will always prioritize high quality habitat in areas that are lower risk for pesticide contamination.

What does this mean on the ground? At the farm scale, we work with farmers and other land managers who want to support pollinators to reduce risks from their pest management practices. We provide individualized technical support to encourage non-chemical management practices that address the root causes of insect pest or disease outbreaks. Working farm by farm can create long lasting change in those environments. You can learn more about our methods through the comprehensive Bee Better Certified program.

When choosing where to plant meadows, flowering strips, hedgerows, and other types of habitat for pollinators, we prioritize locations that offer some protection from pesticide use. For example, pesticide residues generally decline with distance from the site of application, so residues will be lower in pollinator habitat placed farther away from treated fields. Physical barriers, like a drift fence, windbreak, or tree line between habitat and pesticide applications also can limit contamination. While helpful, these mitigations are only a small stopgap measure against the much larger problem of landscape-wide pesticide contamination.
 

Butterfly milkweed (Asclepias tuberosa) blooms on a farm insectary strip in Minnesota (Photo: c. Karin Jokela)
 

Seeking systems-level change in agriculture

Some pesticide risks are too great to be tackled at the individual level. Xerces therefore also advocates for the implementation of systems-level solutions to reduce pesticide use and risks to pollinators. For example, curtailing the practice of prophylactically using pesticide-coated seeds. This practice, which is on the rise in numerous crops, has been linked with contamination across millions of acres in the United States and pose threats to terrestrial wildlife and aquatic ecosystems, in many cases without clear yield benefits.

We also advocate around the risks posed to plants and wildlife by overreliance on herbicides for weed management across millions of acres of herbicide-resistant crops. Broadcast herbicide use and associated drift greatly reduces the available food and shelter for pollinators in agricultural landscapes. Herbicide drift can reduce or delay flowering and seed set of wildflowers, and along with a changing climate, diseases, and invasive pests, may be contributing to widespread declines in trees that host hundreds of species of Lepidoptera - critical food sources for birds and other wildlife.

Systems-level change is thus urgently needed to combat the many interacting threats to our pollinating insects in the Anthropocene, including habitat loss, climate change, and pesticide use. Fortunately, the community of farmers, university researchers, decision-makers, conservationists and others involved in making agriculture more sustainable have a deep base of knowledge and skills. Collectively, we have the capacity to make inroads on these challenging issues.

For myself, when I feel overwhelmed at the scope and complexity of the problems we are trying to tackle, I reflect on the buzzing of insects in habitat I’ve helped to restore, or walk outside to watch the wild and vibrant lives of insects, birds, and other wildlife in the perennial beds I’ve labored to build around my house. We may not have all the answers now, but the solutions remain simple: more wildlife habitat, fewer pesticides.

Additional Reading:

• Guidance to Protect Habitat from Pesticide Contamination
• Insecticide Seed Treatments Threaten Midwestern Waterways
• Systemic Insecticides: A Reference and Overview
• Drifting Towards Disaster: How Dicamba Herbicides are Harming Cultivated and Wild Landscapes