“Is this a BAD bug?” is a common social media question that bugs me.

Labeling bugs as good or bad bug is a human construct. Inherently, they aren’t either. Still, many people fear or hate bugs. The Google algorithm knows this. Type the name of an insect into Google search and autocomplete suggestions include traps, spray, infestation, repellent, nest, and bite. Often those aren’t even relevant options! The $20 billion global Pest Control Industry reinforces this. Orkin and Ortho are frequently top website returns – and not just for pest species!

I look at bugs from the perspective of the “web of life.” All living organisms (animals and plants) in an ecosystem have interrelated roles. When something disturbs the system, the balance is lost. A diverse, fully functioning ecosystem can typically recover from a minor disturbance, although even then there might be rebalanced interdependences.

Wasps help balance bug populations. This wasp controls stink bugs.

Human actions are one of the primary reasons for disturbances. These include (1) destroying habitat for agriculture, housing, and industry, (2) introducing non-native species, (3) contaminating/ killing with herbicides and pollution, and (4) climate change. The result has been a major decline in native insect populations. But more specific to “bad” bugs, these disruptions can create imbalances that struggle to recover – resulting in over-populations that can have real noticeable impact. In other words, humans are responsible for bugs becoming PESTS.

As an example, my husband and I created disturbance when we built our home. The area around the house was stripped of vegetation (mostly non-native plants). We used the first summer to install hardscaping, and plant trees and shrubs. Much of the ground remained bare or mulched. The second spring we started planting native herbaceous plants. Shortly after, the munching started. Yikes! It didn’t take too long to learn why. We had an invasion of grasshopper nymphs. It felt like a plague that first year! But with the second spring, a miracle happened. Actually – rebalance happened. Predators, led by new nesting Song Sparrows, moved in and gobbled up those little instars. By the third year, most of our plants were thriving. Our property has had a balanced population of grasshoppers ever since. For a brief spell, I labeled the grasshoppers in our yard “pests,” but they were just out of balance because of our actions.

Chinese Mantids are indiscriminate non-native predators, so why are they sold as “natural” pest control? This one is eating a Hummingbird Clearwing Moth pollinator.

A different type of disturbance is the unintended or accidental introduction of species to new geographic locations or habitats—like insect stowaways in ship cargo. Fortunately, most insects don’t survive a generation when they’re dropped into an alien habitat. However, some become a minor part of their new environment, where they either co-exist or make small impacts beyond human knowledge. I find many non-native insects in our yard—some species having been in the US for over a hundred years.

Occasionally, accidental introductions like Spotted Lantern Flies (SLFs) and the Emerald Ash Borers (EABs), become disruptors with huge economic implications. Such exotic introductions are happening more frequently. In their native environs, these insects co-exist in balance with natural predators. But away from their native habitats, they have no controls and can create explosive populations. In the case of SLFs, their favored host plant (Tree-of-Heaven) is a widespread invasive tree in the US, so reproduction was easy.

Officials responsible for solutions to exterminate or control invading pests have a primary goal to eliminate economic risk. Unfortunately, short-term solutions often cause additional negative consequences. DDT use to control Gypsy (now Spongy) Moths is an unfortunate historical example that birders know well; DDT has toxic effects on birds and their eggs. More recently here in Pennsylvania, people were initially encouraged to tackle SLFs with glue traps and chemically spraying trees, but that resulted in trapping and killing wildlife bycatch, ranging from insects to birds and even mammals.

Our yard has abundant Seven-spotted (shown here) and Asian Lady Beetles, while native lady beetle species are a rarity.

Humans also intentionally introduce non-native species as “beneficial” predators. Multicolored Asian (MALB) and Seven-spotted (C-7) Lady Beetles were introduced to feed on insects destructive to agricultural crops. It took decades, but MALBs unexpectedly went rogue and became a pest species through massive population explosion and migration. While these invasive beetles aren’t a single direct cause, it’s a rare treat to find a NATIVE lady beetle in my yard.

Three species of Praying Mantids were accidentally introduced to the US. Later, European Mantids were imported for Gypsy moth control. Now, all are sold commercially as “natural” garden pest control (along with C-7 Lady Beetles). Unfortunately, Mantids are indiscriminate ambush predators that eat anything. In my yard they hang on flowers and capture native pollinator species much more frequently than an occasional pest species. All of these invasive species are in Pennsylvania and my yard.

What can you do if you have a disturbance or imbalance of insects in your yard? Letting the situation correct itself can be hard to do, but is often the best solution. Our native insects have predators that we can see like birds, spiders and assassin bugs, but even more that are teeny tiny like parasitic wasps and mites. By spraying chemicals, we kill the predators too. That destroys the chance for natural rebalancing.

However, just like invasive plants that destroy habitat require removal, introduced non-native bugs that reach pest status may need intervention. The challenge in control (forget thinking about eradication) is to disrupt the invasive insect lifecycle with minimal disturbance to other species. We have successfully reduced the Praying Mantid population in our yard by collecting egg cases. They’re visible during the winter and can be destroyed with a soak in rubbing alcohol. For brown marmorated stink bugs and Asian lady beetles, we keep a small wet shop vac (soap filled) to suck up those around the house. When SLFs first appeared in our yard, we had thousands, even tens of thousands. We killed what we could manually. Our neighbor cut down their Tree-of-Heaven. This year we only found about a dozen SLFs.

Collect and destroy invasive species Mantid egg cases to reduce their populations.

We gladly host lots of Flower Fly pollinators because their larvae feed on our aphids.

Here are some suggestions for how we can change our mind-set while supporting balance:

  • Move from controlling nature, to being a partner or steward. Accept that certain plants are going to be partly eaten or have marked leaves.
  • Don’t purchase or introduce non-native insect species as “natural” pest control.
  • Reduce invasive non-native populations of plants and bugs without harming others.
  • Avoid labeling our native insects good or bad.
  • Add native plants and increase plant diversity.
  • Embrace “leave the leaves” and allow a natural messiness.

Karen Campbell, a member of Lehigh Valley Audubon and FocusOnNatives.com, provided the content and images for this article.