Can this moth create a non moth?
Can a member of your family ever give birth to someone who isn't in your family?
We use words like "moth" to describe families of organisms. By definition, their decendants must always be a part of that family. What usually happens is that a word like "moth", over time, describes so many different shapes of organism that we begin sub-dividing the term.
That's what happened with the word "mammal", in a way. Originally, "mammal" described a certain kind of hairy lizard:
but as that organism had decendants, and those decendants were shaped by natural selection and random mutation - which we see going on now in moths - the word "mammal" came to describe many very different organisms:
Do you see what I mean? Originally there was one sort of mammal, one sort of insect. Over time, the number of different sorts of organisms expanded within those terms so that they became very broad categories of organism, but once they might have been as specific as "golden-crested wood finch" might be, now.
Once there was only one sort of moth. Now there are very many sorts of moths, via evolution. The number of sorts of moths might increase to the point where the term "moth" is so broad we stop using it altogether, and we describe some of those decendants as so distantly related that we don't even bother to call them "moths" anymore.