Gardening with Deb Babcock: Here we go again with grasshoppers
August 4, 2013
Steamboat Springs — In 2009 and 2010, the Routt County Extension office fielded many reports of grasshopper infestations, and the calls are coming again this summer. In areas around Elk Mountain, along Routt County Roads 44 and 129 and along Twentymile Road, the infestation is as bad as I’ve seen it in my more than 13 years here. My car window gets smeared with bodies of grasshoppers on my way home from town each evening, and the front of the car is a yellow, sticky mess. Ugh.
Each year, it seems the Yampa Valley has infestations with several varieties of grasshoppers, each with a different life cycle. Needless to say, it is a challenge for gardeners to control damage to their plants from these voracious pests.
Because grasshoppers tend to infest an area for a three- to four-year cycle, chances are that different parts of the valley can expect to see repeat infestations that started in previous years while other parts of the valley will notice a lessening of the pests. So I guess it’s our turn again in North Routt County.
We didn’t experience a dry, warm May followed by a cool, wet June, which might have kept the population down. Instead, it was the opposite this year. So grasshopper hatchlings had perfect weather to grow.
So what can home gardeners do to lessen hopper damage to our prized plants?
Keep an eye out for grasshoppers hatching. They will be crawling along the ground, not hopping. It's easier and more efficient to try to control grasshoppers when they are young. At those early larval stages, they are more concentrated, and it’s possible to treat a smaller area and still get good control.
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A microbial insecticide, known by trade names including Semaspore or NoLo Bait, is only effective against these young grasshoppers. This product will take about two weeks to begin taking effect and must be purchased fresh and used right away. (It has a shelf life of 90 days.)
The young grasshoppers eat this bait and spread disease to other grasshoppers. While individuals have had success with these products, controlled research studies have shown only 30 to 40 percent effectiveness at reducing grasshoppers. What’s good about this product is it only works on grasshoppers and some crickets — not birds, bees or butterflies.
As grasshoppers mature and start heading toward your garden, insecticide treatments will have limited success because there is continual reinvasion by grasshoppers and the product wears off relatively quickly.
A bran bait product called EcoBran was tested by many of us master gardeners several years ago with pretty good success. It targets immature and mature grasshoppers and contains the insecticide carbaryl integrated in bran flakes that are spread on the ground. What I particularly like about this insecticide is its fast-acting effectiveness (I had overnight results) as well as its relative safety. Bran baits are more effective at controlling grasshoppers than the bacterial insecticides mentioned above.
The dry bran flakes are pretty much a grasshopper specific killer while the liquid forms of grasshopper insecticide — acephate (Orthene), carbaryl (Sevin) and malathion — that are sprayed directly on your plants also are effective but will harm beneficial bees, flies, butterflies and hummingbirds that drink plant nectar from sprayed plants. They also leave residue on edible plants that can be harmful to humans. It’s best to spray these insecticides at night or in the early morning when bees, flies and butterflies are less active.
Get the jump on these critters before they get the jump on you.
No endorsement of products mentioned in this article is intended. Always read and follow label instructions.
Deb Babcock is a volunteer master gardener through the CSU Extension Routt County. For more information, call 970-879-0825 or email firstname.lastname@example.org.