When you work outside, you are constantly surrounded by bugs. Bugs of all shapes, sizes, and levels of concern. They crawl on you and buzz around you while going about their daily lives. Apart from being a nuisance, some bugs are extremely detrimental to our crops. As an organic farm, we’re limited in pest control options. There are some organic sprays made from natural ingredients. Most of the time though, we have to rely on other methods such as exclusion netting - mesh netting with very very small holes that allow for airflow but not most bugs to fit through - or manually hunting for and removing larger bugs, such as tomato hornworm caterpillars, from our plants.
But, for every pest bug, there does seem to be a natural predator! By thinking of the farm as an entire ecosystem, rather than just cropland, we can cultivate conditions that allow for a diverse population of bugs and insects, and hopefully encourage natural predators to stick around. Here are some predator friends that we love to see around the farm…
Ladybugs! You know them. You love them. But did you know they’re one of our best defenses against aphids? Aphids shelter in the soil, so exclusion netting won’t keep them off the crops. In addition, there aren’t any organic pesticide options that we’ve found to work well. Aphids come in many (not-so) delightful varieties. We’ve seen black, white, and green aphids all on the one crop before. They pierce the plants and suck out sap. So, when we see ladybugs on those same plants, we do a little jump for joy. Ladybugs and their larvae both chow down on aphids voraciously.
Hornworm Parasitic Wasps! As mentioned above, we don’t have great pest control methods for tomato hornworm caterpillars, and these guys can EAT. One tomato hornworm can decimate a whole tomato or pepper plant in one day. Our best control method is simply hunting for them. Where we see damage to the plants, we literally try to track them down by looking for recent damage and recent caterpillar poop (yes, poop!). They are expert-level at camouflage, so this can be very time-consuming. That’s why when we see a caterpillar with little white cocoons sticking out of it, we say a little “yippee!” Those are the cocoons of the teeny tiny hornworm parasitic wasp. Now, this next bit gets kind of intense. The wasp lands on a hornworm, lays its eggs inside the caterpillar, and then, when the larvae hatch, they feed on the caterpillar from the inside out. They make cocoons on the back of the caterpillar, and then emerge and fly away as more wasps to start the process all over again. If we see a caterpillar with those cocoons on it, we leave it be. We let those baby wasps do their thing - as grizzly as it is!
Minute Pirate Bugs! While we’re on grizzly hunting tactics, I should give minute pirate bugs an honorable mention. These bugs prey on thrips. Thrips are miniscule winged insects that have a particular appetite for alliums - garlic and onion species - and our dahlias. Again, pest control methods are limited. Thrips are so small that they can fit through most insect netting. This includes the exclusion netting on the high tunnels. Our only defense is planting crops through a reflective plastic mulch. The reflected light can confuse the thrips as they fly by and keep them off the plants for a time. Once they find what they’re looking for though, it’s game over. They also pierce the leaves, suck out sap, and prevent the plants from photosynthesising appropriately. They’re also damaging the dahlia petals and making any flowers they get their mandibles into unsellable. So, if we see minute pirate bugs on our crops we dance a little jig. These bugs have a straw-like mouth part that they use to spear their prey. Minute pirates indeed.
Black and Yellow Garden Spider! Ok, this one isn’t that helpful, but it is cool. These garden spiders have taken up residence in some of our high tunnels. They are quite large, and they are sometimes called a zipper spider for the zigzag pattern made in the center of their webs. I do feel terrified whenever I inadvertently walk into one of their webs. They’re completely harmless though – to people that is. It just so happens that we’re also experiencing a grasshopper problem in some of our high tunnels. The grasshoppers eat the dahlias and the hot peppers (apparently they can’t feel capsaicin, or they just like it). Lots of spider webs in the tunnels means lots of grasshoppers fly straight into them and get stuck. That’s one less grasshopper that we have to catch in a bug net and remove (yes, we do this too!).
It’s easy to feel fed up with bugs when you’re swatting at mosquitos and deer flies or watching your favorite crop get devoured by pests. For all the lamenting we do about bugs, we really wouldn’t have it any other way. Farming organically means dealing with the good and the bad that comes from working with the natural ecosystem rather than against it. We’ll continue to eschew traditional pesticides and prioritize the sweet, sleeping bumblebees on our flowers each morning, earthworms hard at work within our soil, and all of our friendly predators keeping our pests in check.
Bugs!!!
Kiersten
P.S. BIG thanks to Julia and Zach for their beautiful, bug photography!
