It’s easy to overlook the quiet heroes in our bonsai gardens—the tiny allies who hunt silently among the foliage, keeping pest populations in check. One of the most effective and underappreciated of these is the lacewing. At first glance, they seem too delicate to do much damage to anything, with their gossamer wings and fluttering flight. But beneath that dainty exterior is a voracious predator whose appetite for aphids, scale crawlers, mealybugs, and mites makes them invaluable to anyone serious about plant health.
For bonsai enthusiasts, especially those of us who prefer to keep our pest control as natural as possible, understanding and encouraging lacewing populations can be a powerful tool. Whether you’re working with deciduous trees like maples or rugged conifers like junipers and pines, lacewings can play a role in preserving the fine ramification and foliage density we work so hard to build.
Lacewings 101: What They Are and How They Help
Lacewings belong to the order Neuroptera, with the green lacewing (family Chrysopidae) being the most familiar and widely beneficial species for gardeners and bonsai practitioners. Adult green lacewings are about half an inch long, with large, translucent wings and golden eyes. They feed mostly on nectar, pollen, and honeydew, but it’s their larvae that do the real work.
Lacewing larvae, often referred to as “aphid lions,” are aggressive hunters. With curved mandibles that inject digestive enzymes into their prey, these alligator-like juveniles consume hundreds of soft-bodied insects over their short lives. According to Cornell Cooperative Extension, a single lacewing larva can consume over 200 aphids in a week—making them highly effective natural enemies in vegetable gardens and ornamental plant collections alike1.
In the context of a bonsai bench, even one lacewing hatchling can make a noticeable dent in a pest population.
The Eggs: A Sign of Hope, Not Harm
The most distinct visual clue that lacewings have found your garden is their eggs. They look like tiny white dots suspended on the ends of impossibly thin stalks, often laid on needles, leaves, or twigs. On pine, they might show up along a single needle, resembling a row of miniature balloons or punctuation marks. While they might be mistaken for something harmful, they’re actually a sign that the ecosystem is working.
The stalk is more than decorative. It serves a critical evolutionary function by spacing out the eggs to prevent the larvae from cannibalizing each other immediately upon hatching—a real risk given their aggressive nature. Once hatched, the larvae drop off the stalks and immediately begin searching for food. They don’t linger. They don’t waste time. And they don’t ask permission.
Why Bonsai Trees Are Ideal Hunting Grounds
Bonsai trees, particularly when grown outdoors or in open-air structures like hoop houses or benches, are vulnerable to infestations. Aphids can cluster on tender spring growth. Spider mites thrive in dry summer conditions. Mealybugs hide in bark crevices and needle clusters. Scale insects attach themselves to trunks and undersides of leaves, often going unnoticed until their numbers explode.
For lacewing larvae, a bonsai pot is a compact buffet. Unlike larger garden plants where pests can spread out and escape, the small size of bonsai trees makes it easier for a single predator to patrol effectively. The reduced surface area and shorter distances between branches give lacewing larvae the advantage of quick access to prey.
Encouraging lacewings in your bonsai garden is not just about pest control. It’s about maintaining a more natural balance—one that minimizes your reliance on chemical sprays and supports a thriving micro-ecosystem.
Natural Pest Control
One of the biggest challenges in bonsai pest management is the collateral damage caused by broad-spectrum insecticides. When we spray for spider mites or aphids, we don’t just eliminate the pests. We also harm the beneficial insects—predators, pollinators, and decomposers—that contribute to the health of the whole environment.
By encouraging lacewings and other natural predators, we reduce the need for those interventions. It’s not always immediate. Nature doesn’t work on our timelines. But over time, a garden with a healthy predator population tends to have fewer outbreaks and a greater ability to recover when infestations do occur.
Lacewings, in particular, are easy to integrate into a natural control plan. Unlike ladybugs, which often disperse quickly after release, lacewing larvae tend to stay put as long as there is prey to eat. They don’t fly. They don’t wander far. They focus on the task at hand. For us, that’s ideal.
Attracting Lacewings to Your Bonsai Garden
If you’ve never seen lacewing eggs in your garden, that doesn’t mean they’re not present. But if you want to encourage more of them, you can take steps to make your garden more inviting.
Planting nectar-rich flowers nearby—especially those with small, open blooms like yarrow, dill, alyssum, cosmos, or coriander—provides food for adult lacewings. These plants can be grown in adjacent beds or pots and help create a more attractive habitat for egg-laying females2.
You can also purchase lacewing eggs or larvae from reputable suppliers. These are often sold for use in greenhouses or gardens but can be deployed in bonsai settings with care. Keep in mind that once released, they need access to prey to survive, so timing the introduction alongside an active infestation can increase your chances of success.
Avoid using insecticides, especially systemic ones like imidacloprid, which can harm lacewings both directly and indirectly by contaminating their prey. Even “safe” insecticidal soaps can disrupt their feeding if sprayed on larvae.
Observing Their Impact: What to Expect
Once lacewing eggs hatch, you likely won’t see the larvae unless you go looking. They’re small, blend in well, and tend to stay in shaded crevices during the heat of the day. But their impact becomes clear when pest numbers begin to drop without any intervention on your part.
If you track pest populations as part of your bonsai care routine, you may notice a decline in aphids or spider mites over the course of a week or two. That’s lacewings at work. If you’re in the habit of using a loupe or macro lens to inspect your trees, you might even catch a larva in action—gripping an aphid with its mandibles or carrying around debris and exoskeletons as camouflage.
Some lacewing larvae are known for this behavior: disguising themselves with the corpses of their victims. It’s a grim but oddly satisfying sign that they’re doing their job.
Lacewings and Bonsai: A Long-Term Strategy
In bonsai, we often talk about patience. About letting trees develop slowly over time. About building structure year after year. The same mindset can apply to pest management. Quick fixes have their place, especially in emergencies, but long-term stability comes from balance—and lacewings are part of that balance.
A bonsai garden that supports beneficial insects is more than a collection of trees. It becomes an ecosystem. One where predator and prey engage in a constant dance, and where intervention is only needed in the most severe cases. That’s not just good for the trees—it’s good for the practitioner, too. Less time spent reacting to problems means more time spent refining, observing, and enjoying the work.
Lacewings are particularly well-suited for this role. The Chrysopidae family includes hundreds of species adapted to a wide range of climates and prey types, making them one of the most widely studied and effective natural enemies in biological control programs3.
Handling Potential Conflicts With Other Practices
Of course, no strategy is without trade-offs. If you’re also introducing predatory mites or lady beetles, you’ll want to be mindful of potential competition. Some lacewing larvae may consume other predators if food is scarce, though in most gardens there’s enough prey to go around.
Certain horticultural oils and sprays used to combat fungal issues may also affect lacewing larvae, especially if applied directly. When treating for fungus or bacterial issues, apply with precision and in the evening, when larvae are less active, to minimize harm.
Monitoring is the key. Know what’s on your trees, know what you’ve released or attracted, and time your interventions accordingly.
The Bigger Picture: Ecological Bonsai Practice
There’s a growing movement among bonsai practitioners to align horticultural technique with ecological stewardship. Whether it’s using organic fertilizers, collecting rainwater, or supporting pollinators, the goal is to work with nature instead of against it.
Lacewings fit perfectly within this philosophy. They’re not a cure-all, and they won’t eliminate every problem, but they move us closer to a garden where things take care of themselves. They remind us that good bonsai practice doesn’t end at the trunk—it extends into the soil, the branches, and yes, even the invisible spaces between trees where insects move and feed and nest.
When I saw lacewing eggs on my Ponderosa pine this summer—dainty white droplets hanging on silken stalks—I didn’t brush them off. I smiled. I left them be. And sure enough, within days, the aphid population on that tree was under control. No spray. No soap. Just a quiet solution already in motion.
Sources
- Hoffmann, M. P., & Frodsham, A. C. (1993). Natural Enemies of Vegetable Insect Pests. Cornell Cooperative Extension. Available via HathiTrust: https://catalog.hathitrust.org/Record/010367402 ↩︎
- University of California Agriculture and Natural Resources. (n.d.). Biological Control and Natural Enemies of Invertebrates. Retrieved from https://ipm.ucanr.edu/home-and-landscape/biological-control-and-natural-enemies-of-invertebrates/ ↩︎
- Wikipedia contributors. (2024). Chrysopidae. In Wikipedia, The Free Encyclopedia. Retrieved July 2025 from https://en.wikipedia.org/wiki/Chrysopidae ↩︎