What started with a brown bug on a window, ended in a kind of nominative determinism, or aptronym!
Carl Stål, from Uppsala, Sweden (Carl Linnaeus resting place!), described this stink bug in 1855. While Halyomorpha halys is originally from East Asia, it is now one of the most successful alien species in the world. I found it in Germany. There are currently (January 2026) 105.000 observations on iNaturalist from East Asia to Europe and North America. Unfortunately they feed on crops like hazelnut, almond, cherries, apricot and other tasty things.
True bugs in the order Hemiptera come in over 80.000 species, of which many are pretty colorful. The 37 species in the genus Halyomorpha are rather brownish though. H. halys’ common name is BMSB, brown marmorated stink bug. My ID is based on the antennae, which have a distinct pattern of dark and white areas. As always, no guarantee on my ID! It’s only the fourth real bug on picmybug.
The name stink bug is not very charming, but points us directly to the smelly defensive secret these bugs can release when threatened. And there my story begins. The substance bugs release is a mixture of different types of organic molecules. Some main ingredients are certain aldehydes. And as often in nature these are not exclusively for bugs, but occur in other organisms as well. Coriander or cilantro (Coriandrum sativum) for example contains the same aldehydes as stink bugs. In fact, the name coriander derived from the Greek word koris for bug or bedbug! It is the bug weed.
So why is it that (some) people like coriander, but not stink bugs? And is that true at all? We know that some people have a genetic modification that so to say spoils their experience with coriander. When you carry a certain variant of the gene OR6A2, you are more sensitive to the unfavourable aldehydes in koriander. This seems to be depending on the region you are born, and lies somewhere between 4 and 20% of the population.
After reading this I wondered if there are people who don’t dislike the smell of stink bugs. And while I’m writing about a brown bug and olfactory receptor genes, I came across Linda Brown Buck (!) and Richard Axel. They published “A novel multigene family may encode odorant receptors: a molecular basis for odor recognition” in 1991, and received the Nobel Prize in Physiology or Medicine (that’s how it’s called) 13 years after. Humans have 1000 genes and pseudogenes for the olfactory system, and thus it is understandable that we have differences in our taste.
If everything is a matter of our genome, let’s check the most smelly animals in the world. Stink bug is one, and skunks are probably the most famous, but some candidates are surprising me. The Tasmanian devil, the Hoatzin bird, the Wolverine, the Lesser anteater, and even the Bombardier beetle must smell devastating. At least to most of us.
There are people who can’t smell bugs, and there are people who are nose-blind to skunks as well. And I’m not talking about anosmia, when you can’t smell anything, but rather selective anosmia. Now back to Uppsala. It was Carl Linnaeus who named Coriandrum the bedbug weed. I wonder if he had the OR6A2 variety…
https://www.nationalgeographic.com/animals/article/can-humans-smell-insects
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