Settlers in the 19th century witnessed blackened skies with trillions of Rocky Mountain locust sweeping across the North American continent in swarms larger than any known biological phenomenon on Earth.
And then all of a sudden they vanished. In fact, the last small swarm was spotted in Manitoba in 1902.
It’s a modern day whodunit that took a century before entomologist Professor Jeffrey Lockwood of the University of Wyoming finally solved it.
Locusts are highly mobile grasshopper likened as the Olympians of the 10,000 grasshopper species worldwide. Locust outbreaks occur on every inhabited continent.
The Rocky Mountain locust or Melanoplus spretus was the despicable black knight of the North American continent. In essence it was the equivalent of an 18th century Darth Vader.
The last major outbreak was recorded between 1874 and 1877. An infestation of at least seven trillion insects destroyed in excess of $200 million of crops – valued today at $123 billion of damage or half the value of the entire U.S. agriculture industry.
In 1875, a swarm measuring 124 miles long by 37 miles wide moved at a rate of 11 mph and an estimated 3.5 trillion locusts devoured an area in North America approximating the size of Connecticut, Delaware, Maine Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont.
Rocky Mountain locust outbreaks were cyclical and driven by drought.
Locust swarms descended from the Albertan, Montanan and Wyoming Rockies in June.
As the locust advanced south and east they mated. Females laid clusters or pods of about 30 eggs and buried them in the soil. Those adults lived for about two months.
Summer hatches underwent five growth phases, matured and hibernated over winter, awakening in the warmth of May.
Populations would accumulate over three or four years before entering biblical plague proportions.
Hot dry weather weakened plants defense mechanisms and increased the nutritional value of the vegetation as sugars and other nutrients concentrated in leaves.
And prolonged droughts sped up the locust life cycle resulting in a faster breeding cycle.
Finally, droughts restricted lush vegetation to swales (well tended agricultural fields), locusts aggregated and then over crowded, ravenous swarms began to disperse en masse.
In addition, these colossal swarms were assisted across the prairies by the Great Plains low-level jet stream.
Prior to European settlement about 45 million bison roamed the plains consuming about 10 million tons of vegetation per annum.
Aperiodic Rocky Mountain locust outbreaks estimated by Professor Lockwood supported 15 trillion locusts as these insatiable insects destroyed about 8 million tons of plant life in one summer.
In the late 1980s, ice cores from Knife Point Glacier, Wyoming unearthed 250, intact, frozen Rocky Mountain locust. They clearly revealed the evidenced of 300 years of outbreaks that commenced in the 17th century.
Lockwood’s team was now able to assemble all the necessary pieces of the jigsaw puzzle and conclusively solve why the Rocky Mountain locust vanished.
In the 1870s more than two million settlers were transplanted across the western North American prairies.
Populations of Rocky Mountain locust spread across Alberta, Montana and Wyoming of say 10 million; each required about 2,200 acres of either river bottoms, sunny uplands or subalpine grassy areas providing a permanent breeding ground, thus enabling swarms to eventually attain trillions of insects.
These permanent populations buried their eggs in well-drained soils.
It just so happened that the permanent Rocky Mountain locust breeding grounds were the exact fertile sites that the early settlers chose to cultivate. Hence egg masses were either flooded to death or ploughed under.
The awesome short and tall prairie grasses of North America were able to sustain millions of bison and trillions of Rocky Mountain locusts.
Now some 300 million Americans’ rely on these exact soils for our daily sustenance – these soils must be very carefully managed.
SAVE THE HONEYBEES http://www.youtube.com/watch?v=l6w-Z7XlnHI
Dr Reese Halter is a public speaker, conservation biologist and founder of the international conservation institute Global Forest Science. His latest book is The Incomparable Honey Bee http://www.amazon.com/s/ref=nb_ss_gw?url=search-alias%3Dstripbooks&field-keywords=The+Incomparable+HoneyBee+reese+halter&x=0&y=0 He can be contacted through www.DrReese.com
