First Firefly Sighting

Last evening as I was walking my dog, I was delighted to see the first firefly for this year. I remember as a child how much we enjoyed watching and chasing the fireflies, which we generally called lightning bugs.  We loved to catch some of them, and put them in a jar with holes in the lid.  In recent years, I have seen fewer of them than in years past.

Fireflies are not really flies, but winged beetles. They are called fireflies or lightning bugs from their use of bioluminescence to attract mates or prey. Many live in marshes or wet, wooded areas where their larvae can find plenty of food.

There are many different varieties, in various parts of the world. Fireflies hibernate over winter in larval form, then in spring pupate and emerge as adults. The larvae of most species are predators, and feed on other larvae, snails and slugs. Adult diets vary, depending on species. Some are predatory, and others feed on plant pollen and nectar.

Firefly populations are dwindling around the world. It is not known exactly why, although it is generally believed because of development, pesticide overuse and light pollution. Most species of fireflies thrive as larvae in rotting wood and forest litter near ponds and streams. Many of their habitats are being developed and paved over, and use of pesticides is removing their food sources.

Another theory is that light from homes, cars, stores and streetlights may make it difficult for fireflies to signal each other during mating, so there are fewer fireflies born the next season.

We don't know yet what individuals can do to help reverse this unfortunate decline, but here are some suggestions that have been made. Some people turn off exterior and garden lights during firefly season, to make it easier for the fireflies to find each other, and keep their blinds pulled at night so interior lights don't brighten their yards. 

Another suggestion is to plant some trees, and allow some natural litter to accumulate in part of your property for larvae to have a place to grow.  I have read multiple reference to some species of adults eating pollen and nectar, but never found which plants they prefer defined.

Creating a water feature such as a pond in your yard is another way to see fireflies at night. Chemically treated swimming pools won't substitute, as fireflies are believed to eat the smaller insects, grubs and snails that thrive in and around natural, nonchlorinated water. It is also important to avoid use of pesticides and weed sprays, which may harm fireflies directly or by killing of their food sources.

Fireflies stay on the ground during the day, and prefer areas of taller grass or plants in which to hide. Frequent mowing may disturb them. Some people suggest that leaving areas of the yard with taller, perhaps decorative grasses or ground cover plants might offer fireflies a place of refuge.

It would be sad to think that fireflies might become extinct.  They add so much sparkle and magic to summer nights.

Update (6/15):  In reply to question on when the mating season is: when your entire adult life is only a few weeks long, and the main goal of that adult life is to mate, it sounds like mating season is whenever you can find other adults of your species.  For some species, it's only about 2-3 weeks long, and it seems to vary from year to year, depending on weather. Most sources just say "summer."

Good luck on finding them for your guest.  On a warm, dry evening, look for places with standing water, tall grass, and low-hanging branches. I've only seen the one so far, but hope there are many to follow.

Update (6/16):  I sat out on my front porch for a while this evening, watching the fireflies dancing through the darkness of my garden.  Seems like there are more of them in my yard now that I've put in the pond and the areas of ground cover than there were a few years ago.