Summary: Locusts swarms have been documented for thousands of years. In today's world locust swarms still exist, but there are steps to take to limit the damage.
Washington receives word from the American Consul in Jerusalem describing a great invasion; the enemy is clearly visible in nearby fields and in the streets of Jerusalem. The enemy's forces number so high in fact that the streets in front of the American Consulate appear to be a river of flowing green and black. A short time later refugees begin to seek asylum in America and elsewhere offering first hand accounts of the aftermath of the invasion: "Flour costs $15 a sack. Potatoes are six times the ordinary price. Sugar and petroleum are unprocurable and money has ceased to circulate.
The reports and first hand accounts could easily lead one to believe that Jerusalem was invaded by an enemy with overwhelming military force. In reality this is the result of a plague of locusts that lasted from March until October in the year 1915. The onslaught of locust spared little. Vineyards, orange groves, melons, apricots and crops were devastated leaving little if anything for the people of Jerusalem.
The massive swarms of locust we have heard about are actually a mass insect migration. Although we do not fully understand the process, certain environmental conditions lead to rapid breeding and a substantial increase in population. In response to overcrowding, the solitary locust will begin to come together in a massive group. Repeated physical contact over a period of four hours will cause the locust to begin to evolve, molting five times, changing color and shape until they are ready to take to the air and begin their migration.
The migrating locust can number in the millions or even billions and have been known to block out the sun for miles. They are capable of flying great distances in search of new feeding grounds. An excellent example of this ability occurred in 1988 when a swarm of African desert locust made the 4-6 day none stop flight from West Africa to the Caribbean; a flight of over 3100 miles.
Some of the largest known swarms are believed to have covered hundreds of square miles rapidly stripping fields and devastating crops. One such swarm was observed in 1874-1875 when an estimated 124 billion Rocky Mountain locust (believed to be extinct) swarmed into the Great Plains destroying millions of dollars worth of crops.
There are ways of controlling local locust populations and minimizing damage from the sudden appearance of migrating locust. Let's say you have a local population and you see locust and locust damage year after year. Locusts die out in the winter and are replaced by nymphs hatching in the spring. To control a local population you start your control efforts in late winter or early spring by spreading Talstar or a comparable product. Talstar PL is a time-release pesticide granule that kills the emerging locust nymphs before they can do any damage or lay eggs, thus breaking the annual cycle. If you are experiencing a long dry period you need to water the pesticide treated area to ensure that the granules properly release into the soil. Despite your best efforts it will most likely be impossible to completely eliminate the problem using early treatments.
If you suddenly find yourself in the path of migrating locust your only option may be a pesticide spray. Cyfluthrin is an odorless pesticide that effectively deters the locust. The locusts that attempt to feed on treated plants will die before they can do significant damage. This method is most effective if you have advanced notice of the migrating locust allowing the treatment to be applied before they arrive. Local farm reports and news provide just such advanced notice.