For many of us, this marks a second truly awful year of grasshopper invasion into our gardens and acreages. At these numbers they are impossible to ignore, creating waves of movement as one walks through their grass, hopping from any possible perch onto clothing or even into hair, and rudely leaving evidence of their presence, even after they’ve left, on every surface imaginable. While our collective distaste is palpable to say the least, is there anything to be done?
To begin answering this, I think it’s valuable to first get a grip on the lifecycles of the over 100 species of grasshoppers that populate our state. Most of them overwinter in an egg stage in the soil. Some soils are better ‘egg beds’ than others so at times you may find that a large hatching will occur in one area in the spring. Generally, they hatch in mid-late spring, first emerging as tiny incarnations of the larger versions we are so used to seeing. It’s this nymph stage that’s the easiest to control. They will then complete up to six instars, or size increases, shedding their smaller older layers and getting larger with each molting.
Unfortunately, grasshoppers will usually live for months and will spend their lives eating, mating, and laying eggs, finally dying off in late summer into early fall. The few that you may see on warm days during the winter are species that overwinter in the nymph stage and can sometimes molt during the winter, reaching an adult stage by the end of the cold season.
The most effective control stems from environmental pressures. Perversely, if we want to see reduced grasshopper numbers, we need to be crossing our fingers for a cold and wet period when they begin to hatch since those first few days are crucial for their survival and the unpleasant weather is highly destructive to them. The same is true of very dry winter and spring conditions that inhibit any new plant growth. Young grasshoppers depend on tender foliage for early feeding and without it many perish. Along the same lines, if we are in drought conditions during the summer and the food sources become extremely scarce, the grasshopper population is also bound to be adversely affected.
Hoping for terrible weather conditions that will have awful systemic impacts throughout our ecosystems is, to me, an unacceptable Catch-22. So, if the weather isn’t helping, what are the other options available to us?
My favored option, using a product called NOLO Bait that weaponizes a nematode, Nosema locustae, to infect and kill the grasshoppers from the inside out, leaving other beneficial insects unaffected, is tragically no longer available for purchase. The factories responsible for manufacturing it were destroyed in a fire and, because it takes a long time to multiply the stock of nematodes necessary for distribution, no one has been able to fill the vacuum as yet.
If you can begin your control measures early in the season and catch the grasshoppers at their youngest stages, a sprayed application of neem oil directly on the insects will often help to control their numbers. However, as they increase in size this method rapidly becomes ineffective.
That brings us to products that use an insecticide applied to a bait such as bran. The grasshoppers will eat the bran, ingesting the insecticide and hopefully die not long after. This is a more appealing method than just spraying insecticides all over the yard and inadvertently killing hundreds of other well-behaved and often beneficial insects. Usually, it is mostly just grasshoppers who are tempted by the bran, so the effect is more targeted and useful.
If you are at all concerned about maintaining the health of your yard’s ecosystem, I strongly suggest you research carefully and thoroughly any other pesticides you are considering applying. Many of these have other effects, long residual lifetimes, and very specific application limitations and practices that can affect your decision about what would be the best fit for your space. Remember also, that systemic pesticides that enter plants’ vascular systems can affect any and all species that feed from the plant.
There are some ‘natural’ controls that can make a dent in populations including Blister Beetles, adult Robber Flies, parasitic flies, and the dining habits of many bird species and mammals such as coyotes, skunks, shrews, and foxes. The effects from these predators are seen as more stabilizing and play a larger role before outbreak levels are reached.
Here in Pueblo, we can take some small measure of comfort in knowing the grasshopper plague we’re enduring is also in full swing not only all along the Front Range in Colorado, but also stretching north into Montana and Idaho. We are not alone, and hopefully this cycle will be broken soon-or some entrepreneurial-spirited soul will start up a new NOLO Bait operation!
In the meantime, you can use mechanical controls to try to save your most precious plants. I have an English rose currently riding out the season swathed in a mesh laundry bag from a dollar store. Row covers can also be highly valuable in instances like this. Other folks I’ve talked to are paying kids and grandkids for each grasshopper dispatched, no questions asked.
If you would like to dig a little deeper into this topic and explore what the more popular species here in Colorado are, just hop online and look up our ‘Grasshopper Control in Gardens and Small Acreages’ Fact Sheet– 5.536.
