Where do you find the dragonfly. Is it only found at a certain generation?

The dragonfly is 1 of 4 rare bugs, which means it doesn't show up as often as the common bugs. The appearance of the bugs seems to be random, not generation specific.

Also, because the dragonfly is partially translucent, it's really hard to spot even when it DOES show up.

Don't forget that the bugs only show up when it's raining. As Krystal says, the dragonflies are particularly hard to spot - the sparkles indicating the presence of a collectible are often hidden to some extent by the rain as well. The bugs seem to appear in two main areas: around the right-hand side of the house from the back door down to the hosepipe near the sand pit, and around the top and left-hand sides of the workroom.

finally found it...it was sooo hard to see...