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# 10: What is a bug?



Litinsects #10: What is a bug?

 Raise your hand 🤚 if you’ve ever used the words “insect” and “bug” interchangeably? I hate to break it to you, but you probably haven’t been using the word bug correctly. You see, bugs are a kind of insect but NOT ALL INSECTS ARE BUGS!

TRUE BUGS make up an order called HEMIPTERA. They can vary widely in their appearance but all share one basic feature: mouthparts modified into a stylet-like ROSTRUM, as you can see on the specimens pictured. Don’t worry, this isn’t some mutant species of legless bug, I just removed the legs so the entire rostrum is easily visible.

Now let’s learn some more about TRUE BUGS:

  • Examples of Hemiptera include: aphids, stink bugs, cicadas, bed bugs, scale insects, planthoppers, shield bugs, and assassin bugs
  • Hemipterans use their piercing sucking mouthparts to feed on a variety of fluids. Most are plant-eaters, using their rostrum to pierce leaf cells and extract plant sap. Some are predatory while others even feed on mammal / human blood 💉
  • A bug’s rostrum has two channels, one for moving saliva outward and the other for sucking liquid food inward. The saliva injected into the food source contains enzymes that actually begin digestion extraorally (outside the mouth)
  • Some bug names can be misleading... for example, ladybugs, love bugs and june bugs are all actually beetles, not true bugs
  • The other defining feature of true bugs lies in their life cycle. All bugs are HEMIMETABOLOUS, meaning they undergo INCOMPLETE METAMORPHOSIS. But that’s a cool topic for another post...
So I leave you with this public service announcement: BUG ≠ INSECT!
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