#640 1996 · Bart Knols / Ruurd de Jong, Wageningen Agricultural University · Entomology / malaria-vector research
Researchers needed a cheap way to lure malaria mosquitoes into traps, so they tested whether a supermarket cheese smells like human feet to a mosquito
问题
Trapping and surveilling the mosquitoes that carry malaria requires a lure that mimics human odor, but human odor itself is expensive and impractical to mass-produce for traps deployed by the thousand
背景
Malaria-vector surveillance and control in sub-Saharan Africa depends on trapping Anopheles gambiae mosquitoes, the species primarily responsible for transmitting the disease, and the traps work best when baited with something that mimics what actually draws the mosquitoes to bite humans in the first place: human body odor, particularly the smell of human feet and the bacteria that produce it.
The obvious source for that lure is human odor itself — sweat, skin bacteria byproducts, worn clothing — but producing or standardizing that signal for traps deployed by the thousand across a large region is expensive and impractical; a lure requiring a live human volunteer, or synthesized replication of dozens of specific odor compounds, doesn't scale to the level a real vector-control or surveillance program needs.
换别人会怎么做
The standard approach to baiting a mosquito trap with the odor that actually draws Anopheles gambiae to bite humans is to use human odor directly — sweat, skin bacteria byproducts, or worn clothing from a human volunteer — since that is definitionally the exact signal the mosquito is evolved to respond to.
他们看到了什么
Knols and de Jong recognized that what actually attracted the mosquitoes wasn't 'humanness' as such, it was a specific set of bacterial fatty-acid compounds present in human foot odor — and that the same ripening bacteria long used to make a completely unrelated, mass-produced dairy product happened to generate a nearly identical chemical signature. The mosquito's trigger wasn't tied to a human source at all, just to a particular smell any sufficiently similar bacterial process could reproduce.
那一手
Entomologists Bart Knols and Ruurd de Jong at Wageningen Agricultural University tested whether Limburger cheese, whose bacterial ripening process produces isovaleric acid and other compounds chemically similar to those responsible for human foot odor, could substitute for human odor as a mosquito attractant. In controlled wind-tunnel and olfactometer trials, they found female Anopheles gambiae mosquitoes were attracted to the cheese as strongly as to human feet, identifying a stable, mass-produced, shelf-stable substance as a viable stand-in for a signal that would otherwise require a live human volunteer or costly synthesized chemistry.
为什么管用
Because Anopheles gambiae's host-seeking behavior is driven by specific volatile fatty-acid compounds rather than any uniquely human biological signal, a substance chemically similar enough in those specific compounds triggers the identical attraction response regardless of its source. Because Limburger cheese is already mass-produced, shelf-stable, and doesn't require live human volunteers or synthesized chemistry to manufacture, it converts an expensive, hard-to-standardize lure into one that's cheap, transportable, and consistent enough to be used in traps at a scale a live-volunteer-based approach never could.
值了多少
The finding, published in The Lancet and Parasitology Today in 1996, earned Knols and de Jong the 2006 Ig Nobel Prize in Biology and became a foundational reference point for subsequent odor-bait trap research. Field-oriented follow-up work built directly on the discovery, including a 2011 open-access study at the University of Nairobi that tested a homemade trap baited with Limburger cheese, heat, and moisture in a Kenyan screen house over 27 consecutive nights, catching Anopheles gambiae mosquitoes and confirming the cheese-based lure's viability in a real trap design, while noting further optimization would be needed before wider deployment.
什么时候会失灵
The substitution only works because the mosquito's actual trigger is a narrow, identifiable chemical signature rather than a broader biological or contextual cue — a target behavior driven by something less chemically specific, or by cues a cheap analog can't replicate, wouldn't yield to the same kind of proxy substitution. Early field trap studies also showed real limits: a 2011 Kenyan field trial using the cheese-baited trap caught mosquitoes at a modest rate over nearly a month and explicitly noted further optimization was needed, meaning the laboratory-proven substitution still required real engineering work before it functioned as a reliable, large-scale field tool.
后来呢
The Limburger cheese discovery remains a widely cited example in vector-control and behavioral-ecology literature of substituting a cheap, chemically-matched analog for an expensive true signal, continues to be referenced in subsequent odor-bait trap design research including field studies in Kenya, and won Knols and de Jong the 2006 Ig Nobel Prize in Biology, a recognition explicitly intended to highlight research that is first funny, then makes people think.
资料来源
- [1]Sampling of An.gambiae s.s mosquitoes using Limburger cheese, heat and moisture as baits in a homemade trapBMC Research Notes (PubMed Central), 2011pmc.ncbi.nlm.nih.gov
- [2]The entomologist who seduced malaria mosquitoes with cheeseImprobable Research (Ig Nobel Prize organization), 2019improbable.com