Fireflies are a sign that summer has arrived. All over the world they are among our most beloved insects. In their adult stage, the only stage most of us recognize, they are like glowing ethereal fairies that spark the night and our imagination. Known by many different names, including lightning bugs, glowworms and candle flies, fireflies are neither bugs nor flies but beetles. Beetles are so important to the health and workings of our planet’s ecosystem that of the over 750,000 species of known insects that live on our planet, beetles comprise over 30% of all insect species. The firefly family, Lampyridae, (Order – Coleoptera), includes more than 2,200 distinct species worldwide. Here in the United States, we have about 170 species. Eastern regions, particularly the mid-Atlantic and southeastern states, have the greatest diversity of fireflies. West of the Rocky Mountains the density of fireflies is lower and the populations are more widely scattered. Like many insects, fireflies are metamorphic, (go through many distinct physical transformative stages in their lifetime). They start their lives first as eggs. In the second stage they become small larvae-like grubs. They scramble through the dark subterranean world just below the top of the soil on the hunt for earthworms, snails and other small prey. At this larval stage, the main goal is to feed and grow. While on their pursuit for food, they aerate the soil thus increasing its health by making tunnels and spaces for rain and oxygen. Even in this intermediate stage, these larvae already light up. With a little luck, on a warm, wet spring or fall night one can see the juvenile fireflies crawling along and glowing dimly as they forage. In the northern part of our country where I live in Massachusetts, because the weather is colder, fireflies will usually spend two years in the larval stage. Farther south, this stage last just a few months. The third and final stage of a firefly’s life is its adult stage. As days get warmer and longer, in late spring or early summer, the firefly larvae will pupate, (change from its intermediary form to its adult form), and emerge as the flying adult that we all know. The adult stage of the firefly is the shortest of its life. As adults they have only a few more weeks to live. Their attention turns from finding food to finding mates thus ensuring their genes will be left in the next generation. Those amazing lightshows that grace our early summer night skies mark a brief but stunning finale to a life that’s been mostly hidden from our view. What purpose does the fireflies flash serve? Bioluminescence, (the production and emission of light by living organisms), is a common trait among sea creatures. We can see its effect at the ocean shore as the waves roll in. Although rare in the terrestrial world, fireflies, a few other insects and some fungi and earthworms have this ability. Scientists have traced the Lampyridae back to a common ancestor that lived more than 100 million years ago. That ancestor’s larvae generated the family’s first sparks of bioluminescence. This ability has been passed down for millions of years to today’s fireflies. Scientists believe that bioluminescence first evolved to help larvae ward off predators. Most beetles are bitter tasting even toxic to insect eating birds and small animals. Fireflies, in both the grub and adult flying stages, use their light as a warning sign to predators to stay away. And since fireflies, both as juveniles and adults, inhabit dark or dimly lit habitats, light is the perfect warning sign. The flashes, flickers or glows that we see are adults signaling each other during mating time. Simply put, the flashes are mating signals. Males and females use these light signals to attract a mate. Males as they fly, advertise their availability with a distinctive flash pattern to the females who are perched below. If the female, waiting in the grass or bushes below, likes what she sees, she responds back with a flash of her own. The pair keep up a flashing dialogue until the male finds the specific interested female and then they mate. Interestingly, each species of firefly has its own specific pattern of flashes so that an appropriate mate of the same species can be found. Worldwide decline of the firefly species- All insect species including the firefly species are declining world-wide. This is due to the use of pesticides on lawns, gardens and agricultural fields, destruction of and lack of habitat and in the case of fireflies, light pollution. A major cause of decline in all insects is the use of neonicotinoids. Neonics, (its short name), is a man-made chemically produced insecticide that until 2017 was the most widely used insecticide throughout the world. It adversely attacks the neurological systems of many insect species especially bees and pollinators. Many pesticides, like neonics are systemic, (spread through the whole plant including the nectar, pollen and roots and into the soil around them). They have a long life and may persist in soils for many years. Because this is where firefly larvae and their prey live, neonics are especially harmful. It is a common practice for many towns and cities to systematically use aerial insecticides that target adult mosquitoes. This activity can be especially harmful when spraying is done at dusk or evening when the adult fireflies are most active. Note: Due to its harmful nature to insects, especially pollinators, most European countries and other countries throughout the world have stopped using neonics. HOW TO HELP FIREFLIES IN YOUR ENVIRONMENT
“Fireflies are tiny messengers that whisper in darkness: Don’t lose hope because magic exists” author unknown
0 Comments
Leave a Reply. |
AuthorConsultant, designer and educator transforming commercial and residential landscapes sustainably Archives
March 2023
Categories |