I woke up this morning with the following item on my news feed "Largest Brood of 17 Year Cicadas to be expected in Spring!" it was shared by a friend and I instantly thought to myself WOW! What a magnificent sight they must be to behold! Evidently, though, the same opinion was not shared by said Facebook friend who included (along with her post) a status update lamenting that "it must be the end of the world!!!" My response to her was typically the same one I came across on this amazing website cicadamania.com :
|Cicada nymph! Aren't they cute???|
The 17 year cicada is not a locust (as they are sometimes confused for) but an insect belonging to the order of hemiptera, or "true bugs". They are of the genus "magicicada" which was named not because the insects are necessarily "magical" in any way, but because they seemed to miraculously appear out of thin air "just like magic" only once every 13- 17 years. In reality though, the sudden "disappearance" of cicadas for such a long period of time after the 4-6 weeks they are active may be attributed to the insect's prolonged developmental phase. Cicada nymphs (which essentially look like smaller versions of adult cicadas but without wings) live their entire lives under ground where they feed on the sap generated by the roots of large trees.
|transformation of the cicada|
from mature nymph to
The nymphs must go through a process of incomplete metamorphosis whereby they undergo 5 molts (or instars) before they graduate as adult cicadas and the process can take anywhere between 13-17 years which accounts for the "sudden" disappearance of the insects for such a long period of time. When they do emerge, however, they often do so simultaneously and in very large numbers! This is thought of to be some form of survival strategy known as predator satiation. Cicadas emerge in the thousands, sometimes even in the millions, which makes it impossible for any predator to completely kill them off! This means that there will be plenty of cicadas leftover to mate and lay eggs, thus ensuring the survival of the species. This phenomenon is unlike that of the locust swarm because while the locust swarm is literally a band of insects that move, breed, and feed as a large group, the cicada swarm is really just a means to an end: ensuring enough adults survive long enough to pass on their genes to the next batch of insects. Indeed, such is the life cycle of most cicada species though the 17 year cicada is the only one to do so in such record numbers.
Other interesting facts about the 17 year cicada
- The 17 year Cicada is also known as the periodical cicada. This is because of their survival strategy of emerging in large swarms over the span of a certain period, as opposed to every year.
- There are a grand total of 7 species that make up the genus magicicada and 4 of these emerge on a 13 year basis.
- The 17 year cicada is perhaps most known for its ability to generate a loud, sometimes deafening sound (as is the case with all cicadas). Male cicadas do this to attract mates and do so by popping a set of muscles on their abdomen known as "tymbals", in and out rapidly.
- Unlike locusts, cicadas do not defoliate entire plants. Adult cicadas possess piercing mouth parts that they use to suck the sweet sap from trees. Slender trees may be damaged by this process, but large stronger trees do fine.
- Last, but not least (this one is my favorite!) 17 year cicadas are affected by the massosporan fungus. An infection that is the equivalent of Cicada STD as it is spread through mating and causes the abdomen of adult cicadas to fall off! (Yikes!!!!)
You can read of such facts, and more at www.cicadamania.com
In conclusion, though the sights and sounds of an insect swarm of such gargantuan proportions can seem like a daunting, even intimidating prospect, when all is said and done... they only come once every 13-17 years! And aside from the loud sounds and the occasional clumsy cicada smack to the face: these insects are really quite harmless which totally begs the question: why can't we all just get along?