In a story that begs references to Alice’s Adventures in Wonderland’s fifth chapter, researchers at the Max Planck Institute for Chemical Ecology in Germany have discovered a nicotine-puffing caterpillar.
While this find may not push Alice’s hookah-smoking insect from its psychedelic pedestal, this caterpillar is pretty snazzy, as it can use nicotine to ward off hungry wolf spiders.
The researchers found a gene in hornworm caterpillars that allows them to puff nicotine out through their spiracles (tiny holes in their sides), from the tobacco they consume, as a warning to their would-be predators. Researchers called this tactic “defensive halitosis.”
The research team discovered this effect while attempting to determine how the hornworm caterpillars had adapted to consume tobacco crops containing concentrations of nicotine expected to be toxic to the caterpillars.
By feeding hornworm caterpillars tobacco plants with and without nicotine, researchers identified the gene that was activated when the caterpillars consumed nicotine-containing tobacco plants. The scientists then placed so-called interference RNA matching that gene in tobacco plants grown in the lab. The interference RNA targeted that gene, preventing the caterpillars from using their defense.
When caterpillars consumed the gene-altered tobacco, they lost their ability to produce the tobacco halitosis and thus their ability to ward off the spiders. As a result, they were consumed at a higher rate by wolf spiders, a rate similar to that found for caterpillars consuming nicotine-depleted tobacco plants.
…and there was much rejoicing among the wolf spiders.
But this research has a higher goal in mind, as the RNA-interference technique they’ve used allows for the targeting of specific genes:
Early trials of medications using a similar principle to treat a rare disease called transthyretin amyloidosis in humans were published earlier this year.
Using these observations, scientists can better answer the question for each gene, “Who are you?”
- Nicotine-Puffing Caterpillar Uses ‘Defensive Halitosis’ To Ward Off Wolf Spider Predators
- Caterpillar Scares Away Predators With Rancid Nicotine Breath
- How smoker’s breath saved this caterpillar’s life
- Caterpillars Repel Predators With Second-Hand Nicotine Puffs