by Carole MacMullan, Fulton County Master Gardener Extension Volunteer
This article is part of Garden Buzz, a series from Appen Media and the North Fulton Master Gardeners, where rotating columnists explore horticulture topics like herbs, insects, and wildlife conservation. Find all Garden Buzz articles here.
As a child, I can remember the thrill of seeing fireflies light up the evening sky. They were so plentiful that we could collect them in a jar, observe them and enjoy the excitement of watching them, turning their lights on and off. Now, I rarely see one or two fireflies at night.
What makes fireflies unique? Both the males and females have the ability to convert some of the energy they obtain from their food to create a flashing light to attract and signal the opposite sex. This biochemical phenomenon is called bioluminescence. If you have been to the beach or a lake at night, you might have noticed water shimmering with light. There are some creatures that live in freshwater as well as saltwater that possess the same bioluminescent ability.

Why are sightings of fireflies becoming more and more of a rarity? A combination of habitat loss and destruction as well as pesticides have created an inability for fireflies and many other insects to reproduce and thrive.
During the last few years, several companies are specializing in residential mosquito spray services. Could the chemicals used by these companies kill more than mosquitoes? No one wants to enjoy their patio, deck or pool or outdoor dining space and find that they are sharing the space with mosquitoes! No one wants to find they are covered with itchy, red splotches after enjoying time outside! Using a mosquito spray company seems to be a solution, but there might be unforeseen consequences!
What is in mosquito sprays? Pyrethrins are the most used insecticides found in residential mosquito sprays. In the perfect world, these sprays would kill mosquitoes and all the fireflies, pollinators and beneficial insects would be spared. Unfortunately, this is not the case! Pyrethrins are broad-spectrum insecticides derived from chrysanthemum flowers. Chrysanthemums have evolved the ability to produce these chemicals to protect themselves from hungry insects. The high concentration of pyrethrins in mosquito sprays indiscriminately kill most insects!
It is my hope that homeowners understand the consequences of using these products and the effect of reducing the insect population on a wide variety of other native insects, birds, amphibians, and reptiles that depend on insects for survival. If we want to live in a mosquito-free environment, there are consequences. You will see fewer fireflies, bees, birds and of course, all the other creatures in our environment that need insects for survival.
Let me share some statistics with you. Every night a single bat can eat 4,500 insects, and barn swallows can consume an average of 850 insects each day! In the past 50 years, the North American bird population has declined by 30 percent through loss of habitat and diminished sources of food. Additionally, the resident toad that appears each night near my garage door needs to consume numerous insects every day to survive.


Please be good stewards of your environment by reducing or eliminating the use of pesticides, planting natives and providing opportunities for insects to lay eggs in leaf litter. Mosquitoes lay eggs in standing water, and their larvae must live in water to develop into adult mosquitoes. To eliminate mosquitoes, identify any sources of standing water in your environment and remove them or add mosquito dunks to fountains and other standing water features. By changing a few ways, you maintain your gardens and landscape, you can help insects thrive, and in turn, you can make a difference that will maintain our food web and enable the survival of our native plants and animals.
Happy gardening!
Learn More
- Georgia Fireflies
- What You Need to Know Before Spraying for Mosquitoes
- Glowing, Glowing, Gone
- Michigan Insects in the Garden-Week 7: Fireflies
- Best Practices of Integrated Mosquito Management

This week’s “Garden Buzz” guest columnist is Carole MacMullan, a Milton resident and master gardener since 2014. Carole describes herself as a born biologist. Since childhood, she loved to explore the out-of-doors and garden with her mother. When she entered college, she selected biology as her major and made teaching high school biology her career for 35 years. Shortly after moving, she became involved with the philanthropic mission of the Assistance League of Atlanta (ALA), completed the Master Gardener program and joined the North Fulton Master Gardeners (NFMG) and the Milton Garden Club. Carole uses her teaching skills to create a variety of presentations on gardening topics for the NFMG Lecture Series and Speakers Bureau. She also volunteers weekly at the ALA thrift store and acts as chair of their Links to Education scholarship program. Her favorite hobbies are gardening, hiking, biking, and reading.