- Author: Harold McDonald
Biological controls seem the ideal solution to insect pests. No poisonous residue to harm the plant—or the consumer if the plant is one grown for food. Unlike broad-spectrum insecticides that can damage beneficial insects along with the pest, most biological controls target a specific organism. While the concept is great—after all, it's nature's way—sometimes the reality may not quite measure up to the expectations. Ladybird beetles fly away, and infestations may just be too overwhelming for the limited numbers of beneficial insects we can introduce. What we really need is more predators that we don't have to introduce, predators that are already in the natural environment.
I live at the west edge of Chalfant, California, where the critters are abundant. By the end of our first season, it looked like our major crop was chicken wire cylinders. That winter I secured the perimeter with a fence of chicken wire, three feet up and one foot under the ground, so the gangs of rabbits that roam the streets of Chalfant late at night no longer terrorize me. The ground squirrels are, of course, another story entirely!
But one of the great things about living out here is that insect pests are relatively few when compared with the well-watered gardens of town. Aphids can be an occasional problem, and I finally decided I couldn't win the squash bug war, but other than that, not too bad. There is, however, one insect that would plague me every summer—tomato hornworms. The moths that hover by the dozens, I love—the caterpillars, not so much!
It was earlier than normal this year (mid-June) that I spotted droppings on the ground. A bit of searching and I had soon discarded a few of the invaders, but I was braced for an onslaught.
Shortly after I had dispatched the hornworms from my tomato plants, my wife reported seeing one of the roadrunners perched on a tomato support, and we began to wonder—could he be looking for the substantial meal that a tomato worm would provide? Though we never observed such a feeding first hand, it seemed that the tomato bushes were of particular interest to him in his patrolling of the yard that he continued throughout the summer.
And the hornworms? I never saw another one, nor any droppings or leaf damage on my tomato plants. Was there cause and effect here? This is certainly the only year I have not had hornworm damage and the only year I have had roadrunners in the yard. While the roadrunner is famous for vanquishing rattlesnakes, they are omnivores, so the rest of their diet is less dramatic: small reptiles and mammals, eggs, fruits and seeds, spiders, insects and worms. Coupled with the interest he seemed to show in the tomato plants, I had been feeling pretty confident that I had my own biological control going on. And now I have located the last bit of evidence that convinces me of that. I just now Googled “roadrunner tomato worms” and found a post from someone in Nevada who saw a roadrunner diving in and out of his plants and coming out with a hornworm in his beak.
Now if only I could get the roadrunners to make my tomatoes ripen earlier!
*Regarding the roadrunner's legendary speed, it isn't quite as impressive as the cartoons would have us believe. Top speed for our greater roadrunner (Geococcyx californianus, how's that for a great scientific name?), a member of the cuckoo family by the way, is a somewhat modest 18 mph. Slower than a human top speed of 28 mph, less than half that of a coyote (43 mph), and not quick enough to get away from a major threat to the species—feral house cats (30 mph).
Selected References
“Greater Roadrunner,” Cornell Lab of Ornithology, October 28, 2011.
“5 surprising facts about roadrunners,” Mother Nature Network, April 26, 2017
“Gigantic, icky green caterpillar on my tomatoes!” Houzz, July 30, 2008.
“Kill the Cat That Kills the Birds?” New York Times Magazine, December 2, 2007.
/span>- Author: Amy Weurdig
I'm by no means a gardening expert. I did somehow succeed in becoming a Master Gardener for the University of California Cooperative Extension here in Inyo/Mono counties, but I have so much more to learn. I still struggle with plant identification – whether or not it's a native plant, a tree, or a sad looking potato plant that I thought was a sick pepper plant.
Last year we moved into our new house in Mustang Mesa in February; but let me spend a bit describing what living on the “Mesa” means in terms of gardening. It's dry, it's hot, and our house backs up to open land filled with sage brush, oh and let's not forget the complete and utter lack of soil. However, all of that cannot detract from the unobstructed view of Mt. Tom or the White Mountains to the east. I honestly, had no idea what to expect in terms of gardening in this location - a new adventure.
It was a busy time since I had ordered bees that were due to arrive in April, gardening season was starting up, and I had so much nesting to do! Not knowing a whole lot about gardening in this area, I planted “Test Garden A” out in the garden area of the corral out back. It included 27 tomato plants (thanks to my husband), shallots, potatoes, Thai peppers, jalapeños, kale, strawberries, radishes and beets. Figured that would give me some sort of idea of what to expect. Note, this was not in raised beds or with irrigation – did I mention I live out in Mustang Mesa?
The bees get put in their hive in the corner to do what bees do and the tomatoes start their vine-y, bunching, and thicket-ing onto each other. The kales gets off to a great start, the strawberries plants are sputtering along. I finally start to see shoots of radishes and beets – oh my!
Then I start to see little nibbles being taken out of pretty much everything but the Thai chilis and the tomatoes- Like big ol' bites! Varmints have found my garden. Brainstorming ideas. I decide to start bending up bits of chicken wire we had stored away from the previous owner of the house, into cute little chicken wire cloches. I saw success for about a week, when the varmints figured out they could just push my cloches over. In came rocks of all shapes and sizes to weight down the cloches. Again, minor success was gained.
The kale that was doing so well but starts to look moth eaten – overnight. I watch and spray and watch some more. Aphids have arrived, complete with their extended families and set up camp in the Kale. They decide to make their way through whatever was left over after the rabbits, and ground squirrels had done their nocturnal dining. Only the tomatoes seemed to have any traction for survival and a few potato plants. So I surround them in their own varmint excluding netted fence, which is not a graceful thing to circumvent. I do see success in the tomatoes and am able to acquire enough to dehydrate, eat, and freeze for future consumption, but not much else was taken out of the garden.
The challenges of all the pounding sun and wind, varmints and debilitating insects led me to have a plot at the Bishop Community Garden (BCG) this season while I plan my attack on building raised beds out on the Mesa in the formal style known as a potager which I think will address my OCD tendencies and entice my darling husband to help raise some vitals.
My garden this year in the BCG has been so very much fun. I've been mentored by two wonderful friends who happen to be dual sport UCCE volunteers. They've aided me with supreme compost, seedling plants, turning over and weeding, switching out soaker hoses for drip lines, nurturing my plants during my knee repair, and have given so much encouragement! I could not have done it without them! I highly recommend having a plot at BCG. By having the plot at the Community Garden, I've learned a lot, been able to meet many new fellow gardeners and had a much better time gardening overall there rather than at at home, where all my work was spent feeding varmints!
I'm looking forward to gardening more out on the Mesa and exploring ways to enrich the experience and to learn better techniques to produce a garden that is varmint/pest resistant – I'm hopeful!