I've noticed the decline in lightning bugs here too, over the last ten or so years. I also noticed one good increase--Monarch butterflies. I had a few stand-alone Asclepias plants out by the road, knowing they were part of the "chain", but never saw one. Then when I got sick and had to ignore my garden the Asclepias appropriated a patch near the front door, darn near smothering the Yuccas. Well, by golly, I've had Monarchs, caterpillars, but no chrysali (chrysalises?). I think the birds may have gotten them. But I saw many Monarchs and a few black-and-blue jobs, and all by my front door! How cool is that? So, note to self: If ya want to plant a plant to attract something, try not to be so stingy and plant a plot of plants!