What is a locust?

All the while growing up, I had to deal with using the term "locust" to describe a cicada.  I studied them as a young lad but easily distinguished between the two widely different species early on.  However, it seemed everyone around me had no idea what a cicada was until I referred to them by their "alias."  It was frustrating to me because even my mother referred to them as that until I enlightened her to their proper name.

 

Luckily that was almost 40 years ago and the times are changing where information/knowledge has become more readily available thanks to the internet and social media.  The alias or incorrect term "locust" is slowing becoming a description of the past.  

 

So, what is a locust then and how did the name become associated with the cicada?  

 

The name "locust" goes way back to the biblical days where certain species of grasshoppers reproduced too rapidly until their numbers became extremely large "swarms."  These swarms attacked crops and stripped the foliage clean on all available vegetation.  These crops were quickly destroyed and as the creatures moved onward; their numbers were so abundant that as they flew, they resembled a storm cloud advancing on a horizon.  Sounds like a thing of a nightmare, right?  They definitely were to the people of those older days.  These creatures are described in the Bible book of "Exodus" and are one of the 10 plagues that Moses warned the Pharaoh Ramesses would come if he did not set the enslaved Israelites free. 

 

A locust can be any number of species of grasshopper and is not designated to a particular one. It is rather given to any species whose numbers can increase to such enormous "swarm" populations that they become a serious pest to agriculture.

 

The locust name went on for generations throughout human history and eventually into the new world.   The year 1633 was the first written account of Periodical Cicadas meeting the settlers of the Plymouth Colony.  Those first immigrants living on the North American shores were not prepared when they first encountered the 17 year cicada.  When those cicadas emerged from the ground in massive numbers, the colonists described them as flies and compared them to the locust plagues of the Bible.  They had thought these insects had arrived to punish them for something they may have done!  The cicada brood involved was probably Brood II which still exists today.  However due to descriptive error, the term "locust" was improperly branded on the cicada ever since.   Dr. Gene Kritsky of the University of Mount St. Joseph in Southern Ohio, researched the historical records and wrote a book called "Periodical Cicadas: The Plague and the Puzzle" describing these events.   The book is available through numerous sellers and I highly recommend it for it's a fantastic read!  (ISBN-10: 188336213X, ISBN-13: 978-1883362133)

Periodical Cicadas:

The Plague and the Puzzle

by Gene Kritsky

 

Indiana Academy of Science

2004

147 pages

ISBN-10: 188336213X

ISBN-13: 978-1883362133

In case you are not familiar with swarming grasshoppers, I will introduce you to a well-known species in the continental U.S.  This particular species is called the Differential Grasshopper (Melanoplus differentialis).  It is approximately 1 1/2 to 2 inches in length and is often a tan, green, or brown color. They belong to the insect order, Orthoptera, which also includes katydids and crickets. Females are considerably larger than males and this species has been known to be a serious pest for farmers when their populations increase to a "swarming" status.  Thanks to advancements in technology, this nuisance species has been kept mostly in check in modern times but can still become an agricultural threat on occasion.    

The life cycle of this insect is very simple.  Their eggs are laid in soil just below the surface.  After mating, a female grasshopper will thrust her abdomen often between crevices and will lay between 40 to 200 eggs in a protective egg mass.  These egg nests will over winter and the young called "nymphs" will hatch the following late spring.  Farmers destroy many of these nests by simply plowing their fields.

After hatching and exiting their underground burrow (or nest), the nymphs, which slightly resemble small versions of their adult forms minus the wings, will immediately begin seeking food.  They have chewing mouth parts and when plentiful, can easily strip a plant of its leaves.  As the nymphs feed, they will go through several nymphal stages, thus shedding their exoskeletal skins and thereby grow a little larger each time.  As they grow, the more they continue to feed.  The nymphs grow very rapidly and can mature in approximately one to two months!  After reaching maturity, they will mate and again lay their eggs in soil, repeating the process.  Like any other fast producing herbivore, you can see how quickly they can become a serious pest and will eat many different types of plant species.

There is normally only one generation per year.

Growing up in Ohio, I've never seen a swarm of true locusts despite living in the western part of the state which it is largely an agricultural area.  The only swarms I've ever experienced are that of Mayflies, which become abundant near the Lake Erie shorelines, and our famous Periodical Cicada!   So now that you have read this, please don't refer to the cicada as a locust!   The two insects are vastly different and the poor cicada doesn't deserve the bad reputation of being an enemy of mankind.  Granted, people living near a cicada outbreak can find their presence quite irritating but try to remember, they only come around for approximately 5 to 6 weeks once every 17 years (typically).  So please try to relax and enjoy the serenade....