Summer nights in the panhandle are unique for their frenetic activity and riotous sounds. In contrast to local February evenings with their silence broken by the occasional barred owl, this summer (technically late spring) month is nearing the pinnacle of activity for bugs, birds and animals of all kinds.
Anyone taking an early evening walk in north Florida between late spring and early autumn has experienced the near deafening calls of cicadas (Magicicada spp.). In days past this earsplitting insect was more commonly identified as a locust in the southeastern U.S. with its mechanical buzzing originating from the protection of foliage in trees and bushes during the day or twilight hours.
It is important to note cicadas are not the infamous locusts of Biblical dread which shredded the green, lush landscapes and foretold widespread famine and starvation. While locust and cicadas are both insects, the similarities end there.
These seldom seen or captured insects known for their raucous, sometimes undulating, chorus do leave strategically placed souvenirs for the sharp-eyed observer. This discarded residue of their early life stages is a highly valued tool for many elementary school boys with a prank in mind. The hard shell is harmless, but under the right conditions does have a certain shock value appreciated by juvenile-minded troublemakers.
Their nymph stage skeletons are often seen on the trunks of trees, shrubs, stalks and even the siding of buildings. The opaque brown shells are abandoned when the cicada outgrows it and emerges to form a new exterior.
Evidence of the cicada’s final molt is usually the only tangible evidence of their presence, but is a useful tool for young pranksters.
The process is similar in other insect species with exoskeletons which provide very limited potential for growth and expansion. The rigid coating provides this creature an armored surface to fend off the challenges of being small in a big, hungry world.
In some states cicadas are famous for their periodic appearance in colossal numbers, sometimes as many as 1.5 million per acre. These once every 13 to 17 year swarms do not occur in Florida which has an insect friendly environment.
The 19 Florida cicada species fall into three groups based on overall size measured by the length of the forewings. They produce their nightly serenade with timbals, paired drum-like structures on the sides of the abdominal segments.
A muscle attached to the timbal plate causes the timbal ribs to pop inward and project outward when relaxed. Flexed rapidly, the cicada chorus can deliver hours of uninterrupted night music.
In Florida only males have timbals and the females are mute. Most sounds made by males are calling songs which serve to attract the silent females.
Cicada nymphs live in underground burrows where they feed on xylem sap from the roots of grasses or woody plants. Because xylem sap is low in nutrients, complete development takes the nymph several years to fully mature.
All cicada species molt four times underground. When the cicada nymph is ready for its fifth and final molt it makes its way to the soil’s surface. It climbs a short distance up a tree trunk or stem, anchors itself and molts for the last time, thereby becoming an adult.
If male, the new cicada will add its contribution to the nightly festivities. If female, she will quietly wait for that special one in a million nocturnal crooner which suits her musical taste.
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