Around 100 trillion insects fly over the contiguous US on summer days. The calculation was based on an analysis by Swiss and US scientists of the NOAA weather radar from 140 sites across 2012-2021. They calculated 100 trillion insects—millions of tons of biomass—flying on average summer days. Thus, radars “see” aerial life overlooked by traditional surveys.
This marks the first continental-scale estimate. Open-access data enabled a decade-long time series, filling gaps in insect monitoring. Previously, studies focused on local species, missing big-picture trends.
Global change pressures insects worldwide. Radars offer automated, cost-effective surveillance at unprecedented scales.
Stable Numbers, Regional Swings
Insect abundance held steady nationally over ten years. However, half of radars detected increases, the other half decreases. Winter temperatures correlated strongest: warmer winters linked to population drops.
Many insects’ life cycles hinge on cold snaps for hatching or parasite control. Consequently, milder winters disrupt balances regionally. Questions arise: Does stability mask species shifts?
Researchers caution pre-2012 declines likely occurred earlier, like 1970s-1990s crashes. Radars detect totals, not species—sensitive ones may vanish while commoners thrive.
Why Radars Change the Game
Weather networks scan skies for clouds, capturing insects too. NOAA’s archive powers retrospective analysis. In the Global South, sparse surveys make this vital.
Elske Tielens of WSL stresses combining radars with local traps and citizen science. Phil Stepanian and Jeff Kelly’s team published in Global Change Biology. Therefore, future models could mine historical data for lost trends.
Broader Implications for Ecosystems
Insects drive pollination, food chains, and nutrient cycles. Declines threaten biodiversity and agriculture. Radar baselines guide conservation amid climate shifts.
Warmer patterns may favor invasives over natives. Policymakers gain tools for large-scale tracking. Thus, early warnings prevent tipping points.
Q&A: Insect Radar Insights
Q: How many insects exactly?
A: 100 trillion (10^14) on summer days, millions of tons biomass nationwide.
Q: Why stable yet fluctuating?
A: National average holds; regions vary, warmer winters hit hardest.
Q: Can radars ID species?
A: No, they measure density—pair with ground data for details.
FAQ: US Insect Skies Explained
What data source proved this?
NOAA weather radars from 140 US sites, 2012-2021 archive.
Stable means no insect crisis?
Not necessarily—hides species losses and pre-study declines.
Winter temps’ role?
Warmer winters reduce populations by altering life cycles.
Global South benefits?
Yes, radars enable monitoring where surveys lack.
Next steps for research?
Blend with local data; reanalyze old archives for history.
