When I started my gardening career, and I hate to admit how many decades ago that was, dealing with bugs in the garden was easy. See a bug? Kill it — preferably with a strong, extremely toxic chemical.
Today my relationship with bugs in the garden is much more complicated. I can’t honestly say that I like most of them any more than I did 50 years ago but I have come to realize that many of the bugs in my gardens are beneficial and need to be nurtured rather than squashed. The problem for me comes in knowing the difference between friend and foe — and learning the most effective, environmentally sound practices to control the enemies.
Although I call them all bugs, not all of the tiny creatures who fly or crawl through my garden are scientifically classified as such. Technically, an aphid is a true bug (Hemiptera), but a spider is an Arachnida while a centipede is a Chilopoda. Regardless of their class, order, family etc, each is an arthropod, which means that each has a body that is segmented, appendages that are jointed and an exoskeleton, which is defined as an external covering used for protection and support. And each arthropod, whether friend or foe to the garden, is a vital and a necessary link in the environmental chain.
In her book, Attracting Beneficial Bugs to your Garden” Jessica Walliser states and there are “two hundred million insects for each living human…and less than 1 percent of the insects we come across in our lives are actually harmful.” She contends that the other 99 percent are either helpful to us or what she terms benign, causing neither harm nor good.
There are, of course, the obvious insect allies that we immediately identify. We recognize that pollinators such as honeybees, butterflies and moths perform an essential service to mankind in pollination and need to be protected and even encouraged.
Getting less acknowledgement of their value is a different group of insects — the underappreciated but beneficial predatory bugs. Predatory bugs eat other bugs. That darling little ladybug (lady beetle) that legend proclaims is good luck is a beneficial predatory insect. In one year, which is the average lifespan of a ladybug, it will voraciously consume over 5,000 aphids. If one female ladybug lays up to 1000 eggs in its lifetime, think how many unsuspecting aphids, mites and whiteflies all of those ladybugs will devour in a season!
Ground beetles are another common beneficial predatory bug that we often disdain. Primarily nocturnal, these smallish brown, black or sometimes iridescent insects often startle us as they scurry for the safety of darkness when they are unexpectedly exposed to light. Although the first instinct may be to squash them, letting them escape is a wiser course. Both adult and larvae ground beetles are carnivores and eat caterpillars, slugs, snails and a variety of other harmful insects. Some species also eat weed seeds, making them doubly valuable.
Like predatory insects, beneficial parasitic insects also dine on other harmful insects. Unlike predatory insects, parasitic spend a period of time attached to or inside of their host. They are typically much smaller than their prey. Although most parasitic insect helpers do their work unseen, their favorable results can’t be missed.
Perhaps the most common and productive is the parasitic wasp, a tiny almost microscopic, sting-less wasp that deposits its eggs inside of its prey. The eggs then hatch and tiny wasps grow inside the host for a period of time. When they have adequately matured, the young wasps escape through a hole they cut in either the head or the body of the host and fly off to repeat the cycle elsewhere. With thousands of species, parasitic wasps attack and kill a huge range of harmful insects including aphids, whiteflies, leafminers and caterpillars.
Relying on beneficial insects to control garden pests requires a huge mindset shift. Living in an era of instant gratification, we have come to expect the same in our pest control. We spray toxic chemicals and get the immediate results of dead bugs. Unfortunately, the chemicals do not differentiate between the “good” bugs and the “bad” ones; the chemicals kill both, which results in some unintended consequences.
One unintended result is the development of a resistance to a particular pesticide, particularly if the same chemical is repeatedly used. Although most pests are killed by chemical applications, some do survive and continue to feed and reproduce. The young become genetically immune to the pesticide and thus more difficult to eradicate.
Another unintended result of unnecessary chemical applications is actually an increase in pest populations. When synthetic chemicals kill off the beneficial pests, then the problem ones have no predators to worry about. Instead, they have an unlimited food source on which to dine. Numbers and types of harmful pests in the garden escalate, making control much more difficult.
Allowing the environmental chain to work as nature intended takes a change of expectations. It means accepting some munched-on leaves and withered stems as a natural element of the garden. It also means having the patience to wait for solutions. Beneficial insects always take longer to appear than their harmful counterparts. Given enough time and tempted with the right buffet, the good bugs will find their way to your garden and begin their amazing work.
Join us next week as we show you how to design a garden that will invite beneficial insects to come for a visit and stay for a lifetime! See you then.