It’s part 2 of our dive into the Insect Apocalypse, with our good friend Dr. Jason Dombroskie from the Cornell University Insect Collection!
In this part, Jason fills us in on the drivers of the Insect Apocalypse and - most importantly - what we can do about it.
This episode was recorded on August 21, 2025 at Rattlesnake Hill Wildlife Management Area in Dalton, NY..
Episode Notes
During the episode, we made the claim that 40 million acres of the US is lawn, and that that area is equal to all of the country’s National Parks put together. True? Well, sort of. The claim that the U.S. has about 40 million acres of lawn—roughly equal to all our national parks combined—is only partly true. A NASA-funded study led by Cristina Milesi estimated that turfgrass covers about 128,000 km² (≈31 million acres) of the continental U.S., making it the largest irrigated “crop” in the country (Milesi et al., Environmental Management, 2005; NASA Earth Observatory). Later analyses and popular summaries often round that up to ≈40 million acres (e.g., Scienceline, 2011; LawnStarter, 2023). By comparison, the total land area of all officially designated U.S. National Parks is about 52.4 million acres, while the entire National Park System—which also includes monuments, preserves, and historic sites—covers about 85 million acres (National Park Service, 2024). So while lawns and parks occupy areas of similar magnitude, lawns do not actually equal or exceed the combined area of the national parks.
Is it better to mulch leaves on your lawn or leave them be? Here’s what we found: It’s generally best to mulch your leaves with a mower rather than rake or remove them. Research from Michigan State University found that mowing leaves into small pieces allows them to decompose quickly, returning nutrients to the soil and reducing weeds like dandelions and crabgrass (MSU Extension, “Don’t rake leaves — mulch them into your lawn”, 2012). Cornell University studies similarly show that mulched leaves improve soil structure, moisture retention, and microbial activity (Cornell Cooperative Extension, “Leaf Mulching: A Sustainable Alternative”, 2019). However, in garden beds, wooded edges, or under shrubs, it’s often better to leave leaves whole, since they provide winter habitat for butterflies, bees, and other invertebrates that overwinter in leaf litter (National Wildlife Federation, “Leave the Leaves for Wildlife”, 2020). The ideal approach might be a mix: mow-mulch leaves on grassy areas for turf health and leave them intact where they naturally fall to support biodiversity and soil ecology.
Episode Links
Find out more about Doug Tallamy, one of the world’s leading proponents of native plants, and, according to Steve, a guy who’s pretty picky about who he hires for his lab.
The End of Night - the book Steve mentioned on the gradual disappearance, due to light pollution, of true darkness from the night skies of most people on the planet.
Links from Part 1:
The Cornell University Insect Collection
Also, check out their great Instagram feed
And their annual October event Insectapalooza
Find out more about the recently discovered species of Swallowtail, Papilio solstitius, commonly known as the Midsummer Tiger Swallowtail- https://www.sci.news/biology/papilio-solstitius-13710.html
Sponsors and Ways to Support Us
Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.
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Works Cited (thanks to Jason for creating the longest list of works cited we’ve ever hard for an episode!)
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