^ Yeah, doesn't the term bug cover arachnidae (that is spiders, ticks and scorpions), centipedes and insects
Really? well, I'm no native speaker in english. Just some random biologist passing by. That might explain my reaction. But okay, I understand the issue.
Yeah, there are a few different meanings to the word "bug" in English. It is used commonly and informally as a term for any kind of small creepy crawly arthropod type critter, but its second more formal definition is the one you are thinking of which is a term rooted in biology which denotes a specific subset of insects with sucking mouth parts.