Ladybirds, also known as lady beetles or ladybugs, are insects belonging to the family Coccinellidae within the order Coleoptera. These small, dome-shaped beetles are recognizable by their bright, often spotted, wing covers and are found across the globe in various habitats. With over 6,000 described species worldwide, the majority of ladybirds are predatory, playing a beneficial role in ecosystems as natural pest control agents.
The Staple Diet: Soft-Bodied Pests
The primary food source for most ladybird species is a variety of small, soft-bodied insects, with aphids being the most common and preferred prey item. Aphids are sap-sucking insects that can cause significant damage to plants, making the ladybird a valued biological control agent. Ladybirds are highly efficient hunters, using their vision and sense of smell to locate dense colonies of these pests on plant foliage.
Once prey is located, the ladybird, whether in its larval or adult form, uses specialized chewing mouthparts to pierce the soft exoskeleton of the insect and consume its internal contents. Beyond aphids, the predatory diet also includes other common garden pests such as scale insects, mealybugs, mites, whiteflies, and psyllids. This broad appetite for high-protein prey helps keep a wide range of pest populations in check.
Consumption Rates Across Life Stages
A ladybird’s consumption rate changes dramatically as it progresses through its life cycle from larva to adult. The larval stage is the most voracious feeder, requiring large amounts of protein for rapid growth. A single larva of some common species can consume hundreds of aphids—often between 200 and 300—before it pupates. This intense feeding period ensures the larva gains enough energy and mass to complete its metamorphosis.
Adult ladybirds continue to be active predators, though their daily consumption is typically lower than that of the growing larva. An adult of the convergent lady beetle, Hippodamia convergens, for instance, may consume approximately 50 aphids per day. Female adults generally consume more prey than males to meet the high energy demands of egg production and reproduction.
Supplementary Food Sources
When soft-bodied prey becomes scarce, predatory ladybirds will turn to supplementary food sources to survive and sustain their energy levels. Pollen and nectar are common non-prey items consumed by many species, providing necessary carbohydrates for energy and hydration. The adult ladybird will often seek out the flowers of plants like dill, fennel, or yarrow to feed on these plant-based resources.
Another supplementary food is honeydew, a sugary, sticky excretion produced by aphids and scale insects. While feeding on honeydew is not sufficient for egg production, it provides an energy boost that can help the adults survive periods of prey scarcity.
Not All Ladybirds Are Carnivores
It is a misconception that all ladybird species are insect predators that benefit the garden; the family Coccinellidae includes species with entirely different diets. Some ladybirds are herbivores, feeding exclusively on plant matter. The Mexican Bean Beetle (Epilachna varivestis) and the Squash Beetle (Epilachna borealis) are examples of phytophagous ladybirds whose larvae and adults feed on the leaves of crops.
Other species are fungivorous, meaning their diet consists primarily of fungi, such as mildews. These fungus-eating ladybirds can be found consuming powdery mildew growths on plant leaves.