Contributed by Libby Coley
SPIDERS! Did a wave of “ewww” just go through your spine? Often maligned and feared, these eight-legged critters should be considered one of our best friends in the garden.
Why, you ask?
Bottom line: spiders eliminate many insects that harm plants, and they themselves don’t harm plants. Where web-spinning spiders are indiscriminate consumers of any bug unlucky enough to get trapped, common garden spiders such as wolf spiders and jumping spiders live on the ground and tend to be more particular about what they consume. These spiders also don’t seek out prey but will only prey on what comes to them.
For example, wolf spiders have the ability to sense vibrations and have sharp vision which allow them to hunt insects by foot. This type of spider lives in underground burrows, often beneath mulch. This makes prey bound to fall into their homes unsuspectingly. Jumping spiders conversely pounce on their prey and tend to go after small winged insects like flies. If they miss a jump, they have a web-like silk that they can produce in order to tether themselves to a nearby plant or tree.
Plant harming insects like mites, aphids, slugs, and earwigs are bountiful examples of harmful insects in your own backyard that spiders help keep at bay. Some things that help increase spider populations are:
- Perennials and groundcovers, which provide spiders with a protected hiding place
- Mulch, which provides spiders with cover and humidity
- Leaving plant stalks instead of pulling them for winter habitat, as spiders live through even harsh New England winter. They are thus one of the first natural control agents that emerge in the spring.
While few of us specifically spray to eliminate spiders, note that it takes a lot more pesticide to kill spiders and these higher levels of pesticide are lethal to other, beneficial insects as well as to us humans! The vast majority of spider species are not poisonous to humans, and here in Massachusetts, only the Black Widow is venomous.
So celebrate and praise your spiders! If you want to learn more about them, check out the SPIDERS ALIVE! exhibit at the Boston Museum of Science running through September 6th. You can find more information about the exhibit here.