Lacewings are delicate, beneficial insects whose larval stage is recognized as a highly effective natural predator in gardens and agricultural settings. The larvae, often called “aphid lions,” consume a wide range of soft-bodied pests, including aphids, mites, thrips, and insect eggs. Attracting and retaining a healthy population of lacewings is a primary goal of natural pest management, as it establishes a self-sustaining control mechanism. The most effective strategies focus on providing continuous food sources, safe shelter, and removing environmental threats to support their entire lifecycle.
Creating Floral Resources and Shelter
Adult lacewings, unlike their carnivorous larvae, rely heavily on plant resources, primarily feeding on nectar and pollen for energy and reproduction. This shift in diet means certain flowering plants must be present to keep the adults in the area, encouraging them to lay their eggs near pest populations. Planting species with small, easily accessible flowers, such as those in the Umbelliferae family, provides the necessary nutrition. Dill, fennel, coriander, and Queen Anne’s lace are highly effective choices for their pollen and nectar offerings.
Composite flowers, including cosmos and yarrow, are attractive to adult lacewings, offering a continuous supply of food throughout the growing season. Plant these resources in dense, staggered masses to ensure a continuous bloom cycle from spring through fall. The constant availability of pollen and nectar directly correlates with the adult female’s ability to lay eggs, boosting the next generation of predatory larvae.
Beyond nutrition, lacewings require safe, protected places for shelter and egg-laying. Providing dense foliage and habitat structures, such as unmanicured hedges or stacked plant debris, offers protection from weather and predators. Adults often seek out these sheltered spots for overwintering, which helps establish a permanent local population.
Minimizing Threats and Environmental Disturbances
The survival of lacewings depends on avoiding materials toxic to both adults and larvae. Broad-spectrum insecticides pose a significant threat, causing direct mortality upon contact and leading to sublethal effects in survivors. These chemicals often prevent larvae from reaching adulthood, even at low concentrations.
Larvae are also vulnerable to indirect poisoning when they consume pests treated with chemical residues. Even if an adult lacewing survives exposure, certain pesticides can negatively impact their fertility and egg viability. Integrating lacewings into a pest management plan requires avoiding these chemical applications. Prioritize methods that conserve beneficial insects, such as monitoring pest levels and allowing minor populations to serve as a food source.
High-pressure water spraying, sometimes used to dislodge pests like aphids, should be reduced or avoided in areas of high lacewing activity. While effective for pest removal, forceful water can dislodge or injure the eggs and larvae. Maintaining a balanced approach that minimizes physical and chemical disturbances is important for lacewing retention.
Strategic Use of Supplemental Food and Water
When natural resources like pollen, nectar, or honeydew are scarce, supplemental feeding helps retain lacewing adults and maintain their reproductive capacity. Commercial lacewing food products are available, often consisting of yeast, sugar, and protein designed to mimic honeydew. A homemade alternative can be created using a paste of brewer’s yeast and sugar mixed with water.
This artificial food mixture can be applied directly to plant foliage or painted onto stakes placed near pest infestations. Providing a consistent, clean water source is also important, particularly during hot or dry periods. A shallow dish or saucer filled with stones or pebbles allows lacewings and other insects to safely access the water without the risk of drowning.
The pebbles must protrude above the water line, creating a secure landing and drinking surface for the insects. Placing this water station in a cool, partially shaded area near flowering plants will make it easily accessible to the adults. Regularly cleaning and refilling the dish ensures the water remains fresh and prevents the growth of contaminants.
Purchasing and Releasing Lacewings
Direct introduction is an effective way to quickly establish a population or manage a severe pest outbreak. Lacewings can be purchased either as eggs or as larvae, with each stage offering different advantages. Larvae provide immediate pest control, but they are more difficult to handle and can resort to cannibalism if crowded.
Eggs are often shipped mixed with a carrier material, such as rice hulls, and are easier to distribute widely. Hold the eggs at room temperature until the first larvae are seen hatching, which signals the optimal time for release. Larvae should be sprinkled directly onto the foliage of affected plants, focusing on pest hot spots, preferably during the early morning or at dusk to reduce exposure to harsh sunlight.
To maximize survival and feeding, misting the foliage lightly before release helps the carrier material and the larvae adhere to the leaves. Releasing the insects near areas of high pest density ensures the larvae immediately find a food source, which is necessary for their development. The adult lacewings that emerge will then disperse, lay their own eggs, and contribute to the long-term biological control of pests.