Droughts, pestilence, famine, and locusts. Does this conjure up images of plagues from the Bible? Well we certainly have at least the drought in large parts of the Midwest. As a kid I remember when it got really dry and hot, the grasshoppers started to show up. I recall unloading oats on hot, sunny early August days and having those little critters hop out of the elevator right into my face. Of course they were harmless to me, but they do claim their share of vegetation. When their numbers swell out of control then can clean off a field. Thank goodness this is rare. But it got me thinking, are conditions ripe for an outbreak?
As it turns out, in order to have a big grasshopper invasion you need to have a few favorable years for their development followed by a near perfect year. Generally, warm and dry spring and summers increase their egg laying, speed up maturity, and minimize fungus and diseases which tend to wipe them out. Factors like cold, wet spells after an early warm dry start to spring can mess them up. Now we did have that cool, wet period in April after the dry, hot March. I wonder how that will play into it? Also if the drought and hot temperatures get too intense, that can stunt them as well, by limiting their food sources. It seems like the perfect grasshopper population set up is to have a warm, overall dry summer with just enough periodic rain to keep the vegetation growing.
You can learn much more about grasshopper biology, life cycle, and management from the following link as put together by North Dakota State University Ag Department. http://www.ag.ndsu.edu/pubs/plantsci/pests/e272-1.htm#Life
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This post was written by Tony Schumacher on July 9, 2012