Isn’t bug a catch all term? Doesn’t have to mean insect does it?
A “true” bug is an insect in the order Hemiptera. It is a term that is applied incorrectly by most non scientists (entomologist) and even some common names are misused. A ladybug is actually a beetle. A bed bug is a bug. When writing the name, if it is not a true bug it is written as one word. A true bug’s name should be written as two words. Another example is firefly(a beetle) and house fly (a real fly). Enough trivia.