201 Peterson Drive
Elizabethtown, Kentucky 42701-9370

Amy Aldenderfer, County Extension Agent for Horticulture

Fireflies can help control garden pests

Fireflies evoke memories of a childhood chase. You’d catch one in your hand and wait to see the flickering light and then moments later, release it unharmed and watch it fly away.

This summertime favorite does more than generate entertaining childhood memories. They also help control some pests in your garden. On summer nights, glow worms (luminescent firefly larvae) often emerge from their underground homes to forage for food. A typical menu includes slugs, snails and caterpillars including cutworms. The larvae feed much like a spider by injecting a paralyzing toxin into their prey; then, injecting digestive juices to dissolve the prey and allow it to be more easily consumed. The adults probably feed on plant nectar to sustain their energy requirements.

There are several theories about why fireflies glow. One is that the flashing light is a homing beacon for the opposite sex. The male flies around flashing the signal to attract a female’s attention. A female on the ground or on low-growing foliage will signal back when a male visits her vicinity. To avoid confusion, each firefly species has its own specific signal to attract a mate.

                In addition to garden pest control, fireflies are used in medical and biotechnical research.  Fireflies produce an enzyme called luciferase to produce their glow.  Because this enzyme uses natural energy in cells, the luciferase can be injected into human tissue to determine whether cells are functioning properly based on how much light they produce.  The luciferase gene also is used in biotechnology to determine if genes have been properly inserted into chromosomes.

Another theory is that firefly larvae use their luminescence to warn a potential predator that they taste bad. Larvae contain defensive chemicals in their bodies. When disturbed, larvae also increase their glow’s intensity and frequency.

Typical nighttime habitats for adults and larvae take place in rotting wood or other forest litter, or on the edges of water sources such as streams, ponds, marshes and ditches. The highest species diversity is in tropical Asia and Central and South America. Incidentally, some Asian species have tracheal gills that enable them to live under water where they feed on aquatic snails.

To attract fireflies to your property, reduce or eliminate lawn chemicals. Add low, overhanging trees, tall grass and similar vegetation to give adult fireflies a cool place to rest during the day. Reduce extra lighting on your property because this light interferes with fireflies’ luminous signals, making it harder for them to locate mates in the area. Fireflies also determine the time of night they’ll flash by the intensity of ambient light. This is why you don’t see many fireflies flashing on clear nights with a full moon.

Source: Rick Durham, extension horticulture specialist

For more information about butterfly gardens, contact the Hardin County Cooperative Extension Service at 270.765.4121, email:  Amy.Aldenderfer@uky.edu contact me on Facebook, or on the web: http://hardin.ca.uky.edu/  Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expression, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability.

NOTE:  The last of the Gardener’s Toolbox Classes are here!

Perennial of the Year—June 6, 6 pm. COST: $5  Every year the Perennial Plant Association  bestows one exceptional plant the title of “Perennial of the Year”.  Find out what plants made the cut for the past 20 years.  You may even get to take one home and try it!


How to Register: 

· Go to http://hardin.ca.uky.edu/content/line-class-registration to sign up for any class.  You can also now make your payment on this page! 

· Or call (270) 765-4121 and talk to the receptionist.  Then mail in your payment.

· You will be registered on a first pay, first registered basis.  All classes have a maximum number of participants.  When this number is reached, there will be a waiting list.

Payment for each of the Gardener’s Toolbox classes are required to be enrolled ONE WEEK prior to the class date. You will be registered on a first pay, first registered basis.

Cancellations will be fully refunded ONE WEEK prior to the class date. Please let us know as early as possible if you have to cancel, we probably have others on a wait list.

HOW TO GROW Classes: If you would like to attend the class but do NOT want the supplies, there is the option of not paying the class supply fee. Please notify the front desk when registering.

NOTE #2:  The Lincoln Trail Area Master Gardeners’ 19th Annual Master Gardener Plant Fair: MAY 20th from 8 a.m.–3 p.m. at the Hardin County Extension Office, 201 Peterson Drive, Elizabethtown. Rain or Shine! (hopefully, shine.)