Is clover good for attracting fireflies?

Fireflies seem to be much more common in yards and grassy areas where lawn treatment and pesticides were never applied. Some experts say the firefly larvae is killed in spring lawn treatments. It could also be because they feed on snails and slugs which might also have been eradicated with pesticides and chemicals.

I've noticed the evenings where I water just before dusk - my firefly count is quadrupled. I'm not sure if its the moisture that's bringing the fireflies or the promise of slugs in the damp areas. On evenings I don't water - I seldom see fireflies. Water the shadiest areas and the areas with most vegetation just before dusk and that will help attract fireflies.