The story of a caterpillar that desperately needs a breath mint is the latest tidbit of offbeat viral information to make its way around the internet. Science is almost always fascinating, but sometimes it’s both fascinating and disgusting. Such is the case of the tobacco hornworm, which gobbles nicotine like it’s eating Doritos at a sleepover. Its breath is just as bad as if it had been noshing on those cheesy corn crisps, too. In fact, it’s so bad that there’s a name for it, and it’s pretty gross: “defensive halitosis.”
While most people have met a teacher or even a dentist who suffered from what could easily be called “defensive halitosis,” perhaps no human has quite this level of offending respiration. The caterpillar in question ingests a huge amount of nicotine relative to its size each day. In fact, it chows down on the nicotine equivalent to that found in an entire cigarette. To understand the enormity of just how much nicotine that is, the caterpillar is smaller than a cigarette, so the amount seems like it would be similar to a human eating as much nicotine as is in hundreds, maybe even thousands of packs of cigarettes. Yuck.
Contrary to the drastically negative health benefits a human would suffer if he or she did something like that, the caterpillar actually relies on the nicotine for its very survival. Apparently, this particular type of caterpillar has the potential to fall prey to a specific type of spider called the wolf spider. However, it turns out that wolf spiders are as offended by disgustingly stinky breath as humans are, or maybe even more so. During a recent study, when tobacco-filled caterpillars were confined with wolf spiders, the spiders said “no way Jose” to what would have otherwise been a delicious feast- they refused to eat any of the caterpillars who had ingested the large amount of nicotine. This is one caterpillar that needs a breath mint, but nicotine keeps him alive.
Scientists were able to tell that it was definitely the nicotine keeping the spiders at bay because when presented with caterpillars that had eaten nicotine-free tobacco, well, the spiders had a field day and the caterpillars did not fare well at all. In fact, the spiders behaved like Joey Chestnut at a hot dog eating contest; they didn’t leave a scrap of tasty caterpillar behind.
The study authors explain in slightly more scientific terms:
Spiders usually assess their prey after capture by tapping it with chemosensory endowed legs and palps. Wolf spiders were clearly rejecting nicotine-fed larvae before penetrating their prey with their mandibles to inject their mixture of digestive enzymes and poisons.
These nicotine fiends are in luck, too, because their bodies are totally immune to the bad health effects with which nicotine is usually associated. If a human ingested that amount of nicotine, they could almost surely expect to experience a large host of deleterious health effects, including various cancers and heart disease.
The caterpillar that needs a breath mint eats enormous amounts of nicotine, but this habit keeps him alive. Who knew defensive halitosis could be such a good thing?
By: Rebecca Savastio