Scarcity of food resulting from the swarm's attack would bring the population to subsistence intake or less, would make the spread of disease among a weakened populace easier, would eliminate any trade from surplus food products, and would stimulate high inflation in the costs of food products. It was only in 1921 that the mystery of the locust was solved. Prior to this date researchers wondered what became of the locust during the years in which there were no outbreaks. In 1921 B. P. Uvarov demonstrated that the swarming locust was none other than an ordinary species of grasshopper. However, when moisture and temperature conditions favored a large hatch, the crowding, unceasing contact, and jostling of the nymphs begin to stimulate changes in coloration, physiology, metabolism, and behavior, so that the grasshopper nymphs make the transition from solitary behavior to the swarming gregarious and migratory phases of the dreaded plague.
Plagues continue as long as climatic conditions favor the large hatches.
Once entering their gregarious phase, swarms, of locusts can migrate great distances and have even been observed twelve hundred miles at sea. I remember being very overwhelmed with the tragedy. Every individual is affected and mourns. One result of the devastation was that there was no grain to make offerings to the Lord, consequently, their sacrifices had to stop and their relationship with God was severed. Perhaps that was part of God's plan.