Behaviors: Cicada Adults Feeding, Defenses, Mating, Agressiveness, etc.
"Adult Tibicen Cicada Feeding"
Back
in the 1970's when I discovered My
First Cicada and started reading up on them, books of that era made
note of the fact that Cicadas did not feed when they were adults. Their
sole primary function when living above ground was to perpetuate the species
by reproduction as their life span as adults was 7 to 10 days maximum. This
of course was later to be proved false.
In
fact Cicadas do indeed feed above ground. Cicadas have a unique mouth part
for feeding known as a "beak". It is a stylus-type protuberance
used for piercing small twigs in trees and bushes to withdraw Xylem
to obtain water, minerals and limited carbohydrates. When a Cicada is not
feeding this beak rests ventrally between the legs.
The
Cicada's beak is actually made up of mandibles, maxilla, a salivary channel
and an outer labium. It's this labium that you can see. It is believed that
feeding for Cicadas serves two purposes. One is for nutrition and the other
is to aid in regulation of body temperature by way of evaporative cooling
on long hot summer days.
Cicadas actually work their beak into a branch for feeding by slowly rocking back and forth from left to right and sometimes up and down. Cicadas can feed sometimes up to several hours. While observing Cicadas feeding, an unusual behavior has been noted. As the below pictures indicate several specimens of both T. lyricen and T. canicularis actually raise their front forelegs in the air and maintained this position while feeding. Position doesn't seem to matter. Whether the Cicada is resting on top of a branch or below a branch, the same behavior has been noted.
Feeding Tibicen canicularis Cicadas
Feeding Tibicen lyricen Cicadas
When handling a Cicada, it sometimes can mistake it's handler for a branch and attempt to feed on you. There is a slight pressure at the point where the Cicada attempts to insert it's beak into your skin. It doesn't usually draw blood. However, I try to avoid allowing a Cicada to do this because I fear pathogens may be carried from the Cicada to me should the Cicada succeed in breaking the skin when attempting to feed.
It is unclear if Cicadas have a particular food preference. The Cicadas that I studied in captivity fed on lilac or maple branches emersed in water. The maximum amount of time these specimens lasted in captivity was 7 to 10 days. An interesting experiment for next year would be to see if Cicadas had a preference for feeding on representatives of their host plant. For example, if a Cicada developed below ground as a nymph feeding on Xylem of an Ash tree, would the same nymph, as an adult only prefer Xylem from the branches of an Ash tree? How far would they wonder from their original host plant as an adult?
"Adult Tibicen Cicada Defense Mechanisms"
As an adult, Cicadas can rely on several defense mechanisms in order to aid their survival.
Predator
Foolhardiness - Unlike Periodical
Cicadas which rely on predator foolhardiness to survive, Tibicen Cicadas
are the exact opposite. The slightest sense of danger from a predator will
send them flying off in a flash. If you happen upon a male, in some instances
a brief alarm squawk may be heard just prior to it taking flight. What is
believed to help Tibicen Cicadas in detecting predators is their 3 ocelli
that are centered in the middle of their head. Yes, Cicadas have 5 eyes.
Two large compound eyes which are situated on stalks on either side of the
head and 3 ocelli which are centered in a triangle in the middle of the
head. It's these ocelli that detect changes in light and may give the Cicada
a slight advantage over their predators. The image to the right clearly
shows 2 of the three ocelli on the Tibicen lyricen Cicada picking
up the light. (The two white dots in the middle of it's head.)
Playing Dead - As previously stated under Nymph Defense Mechanisms, the playing dead behavior is probaby a carry over from the nymphal stage. As in the 5th Instar Nymph, an adult Cicada will lie very still as if playing dead with all six legs tucked ventrally against it's body if it feels threatened. The thumbnails below show the same Cicada playing dead as a nymph then exhibiting the same behavior over several days. The last thumbnail is a brief movie showing this behavior.
Alarm Squawk - When startled or handled, an adult male Tibicen Cicada will issue a loud squawk. It is believed that this alarm is designed to startle a predator into letting it go or dropping the Cicada. Unfortunately female Cicadas do not exhibit this behavior because they do not have the necessary organs for this function, namely tymbals.
"Mating"
"Aggressiveness"
"Sleeping"
More coming soon please check back.
