Cicadas

The loud insect buzzing you hear coming from trees in the daytime is most likely from cicadas. The brown, shed exoskeletons they leave on tree trunks and shrubs mark their presence.

Cicadas are found throughout North America, including here in Florida.

Sound

The sound of cicadas is distinctive and species can be differentiated by their calls. Only males, however, can make sounds, most of which are calling songs to attract mates.

The whirs and buzzes of cicada songs can be similar to the sounds of power tools. Some homeowners and contractors have even reported cicadas being attracted to their lawnmowers and power saws.

The reason only male cicadas can produce songs is that they are the only cicadas that have timbals—drum-like body parts on the sides of their abdomen. The timbals are a combination of stiff ribs, flexible membranes, muscles, and air sacs that pop in and out and produce sound.

Life Cycles

Cicada nymphs live underground where they feed on sap from the roots of trees, grasses, and woody plants. Not much is known about how long cicada nymphs stay underground—some species seem to have two-year life cycles, others ten or more years.

Nymphs will molt four times underground, then climb to the soil surface and up a tree or shrub, and molt a fifth time to become an adult. The skeleton left after this last molt is what people find anchored on tree trunks and other plants.

Cicada adults are strong fliers that will spend most of their time in trees, eating, singing, mating, and laying eggs before they die a few weeks after emerging. When the eggs hatch, the nymphs fall to the ground and burrow into the soil, starting the whole process over again.

Population Cycles

Keep in mind that though species have certain life cycles, not all their broods in the soil are at the same stage in their life cycles. The overall adult population will depend on the size of the broods that were at the end of their nymph stage that year.

Periodical cicadas are species that have synchronized their development so that they mature into adults in the same year, usually on thirteen or seventeen year life cycles. News reports and interest pieces are popular around the time these group emergences are expected.

Florida, however, does not have periodical populations of cicadas, and adults emerge every year from late spring through the fall.

Cicadas in Florida

Cicadas are not considered to be a pest of any significance in Florida. They do not require treatment and are best left alone, since any damage they cause is negligible.

Cicadas are active in tree canopies and shrubs in the daytime; they will not swarm or be attracted to people (nor will they be splattering on your vehicle).

Sometimes their egg-laying can damage tree twigs. The twigs will break, and the leaves die, causing brown “flags” at the end of branches. This problem is rarely reported in Florida because we do not have large periodical cicada populations.

Cicadas do not bite or sting and do not carry harmful diseases. They are a food source for wildlife and even have served as a food source for people.

Table 1. Selected cicada species in Florida.

Common Name	Scientific Name	Found In
Small (Wing length <7 mm)
Little brown cicada	Melampsalta calliope	Meadows
Little green cicada Total length about 19 mm (3/4 in)	Melampsalta floridensis
Medium (Wing length 23 – 32 mm)
Bequaert's cicada	Diceroprocta bequaerti	Western Panhandle
Glass-winged cicada	Diceroprocta vitripennis	Panhandle; oaks
Hieroglyphic cicada Total length about 32 mm (1 ¼ in)	Neocicada hieroglyphica	Oaks
Olympic cicada	Diceroprocta olympusa	Pines, waste fields
Seaside cicada	Diceroprocta viridifascia	Coastal
Large (Wing length 31 – 57 mm)
Dog-day cicada Total length about 64 mm (2 ½ in)	Tibicen canicularis
Keys cicada	Diceroprocta biconica	Keys, Everglades