Ladybugs, also known as lady beetles or ladybirds, are small, dome-shaped insects belonging to the family Coccinellidae. These bright-colored beetles are a common sight in gardens worldwide. True ladybugs are considered beneficial insects in horticulture because their natural behavior helps protect plants from common pests.
The Primary Role of Ladybugs in the Garden
Ladybugs are highly effective biological control agents that naturally manage pest populations. Their diet consists almost entirely of soft-bodied insects that feed on plant sap and foliage. The most significant prey for both adults and larvae are aphids, which can quickly overwhelm a plant by sucking its vital fluids.
Ladybugs also actively hunt and consume scale insects, mealybugs, mites, and insect eggs. An adult female must consume a high-protein diet before laying eggs that hatch into the larval stage, which is arguably the most voracious predator.
The tiny, alligator-shaped larvae are exceptionally efficient hunters. A single larva can consume hundreds of aphids before it pupates, offering significant pest control. By eliminating these damaging pests, ladybugs protect plants from physical harm and disease transmission.
Harmful Insects That Resemble Ladybugs
Confusion arises because a few species within the broader beetle family look similar to the beneficial ladybug but are actually plant pests. The most notable example is the Mexican bean beetle (Epilachna varivestis), one of the few herbivorous members of the lady beetle family. This insect feeds directly on plant tissue, preferring beans, peas, and other legumes.
Unlike the predatory ladybug, the Mexican bean beetle is yellowish-orange to coppery-brown and has eight black spots on each wing cover. Its feeding behavior is destructive, as the adults and larvae chew through the undersides of leaves, leaving a lace-like skeletal pattern.
Another common look-alike is the multicolored Asian lady beetle. This species is also predatory but is often confused with native species. It has a distinct black “M” or “W” marking on its head shield and can become a household nuisance by seeking shelter indoors during colder months.
Attracting and Keeping Ladybugs in Your Garden
To keep a healthy population of ladybugs, gardeners must provide the necessary food and habitat. The most important step is to stop using broad-spectrum chemical pesticides, which kill beneficial insects just as easily as they kill pests. Ladybugs also require sources of pollen and nectar to supplement their carnivorous diet.
Planting companion herbs and flowers with umbel-shaped flower heads, such as dill, fennel, cilantro, and yarrow, provides these nutritional resources. These plants offer a convenient landing pad and a source of pollen that helps sustain adult ladybugs.
Providing a shallow water source can also encourage the beetles to stay. If you purchase and release ladybugs, release them at dusk near infested plants after lightly misting the area to encourage them to settle down.