What's new on Cicada Mania?
As North America enters Fall, it's time to turn our attention to the wonderful cicadas of Australia. Look for Australia-related cicada posts on our blog throughout the months with R in their names.
2015 Highlights so far:
What are Cicadas?
An illustration of cicada tymbals from C.L. Marlatt's The Periodical Cicada. c shows the muscles and tendons connected to the tymbals, and d & e show the bending of the tymbal.
Cicadas are insects, best known for the songs sung by most, but not all, male cicadas. They make this sound by flexing their tymbals, which are drum-like organs found in their abdomens. Small muscles rapidly pull the tymbals in and out of shape — like a child's click-toy. The sound is intensified by the cicada's mostly hollow abdomen. Female and some male cicadas will also make a sound by flicking their wings, but it isn't the same as the song cicadas are known for. Listen to some of the songs cicadas sing.
A Magicicada drinking from a tree. Photo by Roy Troutman.
Cicadas belong to the order Hemiptera, suborder Auchenorrhyncha, superfamily Cicadoidea and families Cicadidae (the vast majority of cicadas) or Tettigarctidae (only two species). Leafhoppers, spittle bugs and jumping plant lice are close relatives of the cicada. Hemiptera are different from other insects in that both the nymph and adult forms have a beak (aka rostrum), which they use to suck fluids called xylem from plants. This is how they both eat and drink.
The Latin root for the word for cicada is cicada. Cicadas are called semi in Japan, cigale in France, and cigarra in Spain. Names for cicadas in countries around the world.
Cicadas begin life as a rice-shaped egg, which the female deposits in a groove she makes in a tree limb, using her ovipositor. The groove provides shelter and exposes the tree fluids, which the young cicadas feed on. These grooves can kill small branches. When the branches die and leaves turn brown, it is called flagging.
Once the egg hatches the cicada begins to feed on the tree fluids. At this point it looks like a termite or small white ant. Once the young cicada is ready, it crawls from the groove and falls to the ground where it will dig until it finds roots to feed on. Once roots are found the cicada will stay underground from 2 to 17 years depending on the species. Cicadas are active underground, tunneling and feeding.
After the long 2 to 17 years, cicadas emerge from the ground as nymphs. Nymphs climb the nearest available tree, and begin to shed their nymph exoskeleton. Free of their old skin, their wings will inflate with fluid and their adult skin will harden. Once their new wings and body are ready, they can begin their brief adult life.
Adult cicadas, also called imagoes, spend their time in trees looking for a mate. Males sing, females respond, mating begins, and the cycle of life begins again.
Top, Left to Right: cicada egg, freshly hatched nymph, 2nd and 3rd instar nymphs. Bottom, Left to Right: 4th instar nymph, teneral adult, adult. (Photos by Roy Troutman and Elias Bonaros).
Different Types of Life Cycles
There are three types of cicada life cycles:
- Annual: Cicada species with annual life cycles emerge every year, for example, Swamp Cicadas (Tibicen tibicen) emerge every year in the United States, and Green Grocers (Cyclochila australasiae) emerge every year in Australia.
- Periodical: Cicadas species with periodical life cycles emerge all together after long periods of time, for example, Magicicada septendecim will emerge every 17 years (Find out where they'll emerge next).
- Proto-periodical: Cicada species with proto-periodical life cycles might emerge every year, but every so many years they emerge in heavy numbers, like the Okanagana.
There are over 190 varieties (including species & subspecies) of cicada in North America, and over 3,390 varieties of cicadas around the world. Cicadas exist on every continent but Antarctica.
According to the University of Florida Book of Insect Records, the Tibicen pronotalis is the loudest cicada in North America, and can achieve 108.9 decibels. Australian species of cicadas, like the Double Drummer (Thopa saccata) are said to exceed 120 deafening decibels at close range. The loudest cicada in the world is supposed to be the Brevisana brevis, a cicada found in Africa. At a distance of 50cm (~20") B. brevis reaches 106.7 decibels.
The most well-known cicadas in the North America are the Magicicada periodical cicadas, which have amazingly long 17 or 13 year lifecycles. Brood IV (17 year life cycle) will emerge in IA, KS, MO, NE, OK, and TX. Brood XXIII cicadas (13 year life cycle) will emerge in AR, IL, IN, KY, LA, MO, MS, and TN, in 2015. Read more about where and when.