Ladybirds (known as ladybugs in North America) are among the most beneficial insects a gardener can have. Both the larvae and adults of most ladybird species are voracious predators of aphids and other soft-bodied pests, making them one of nature's most effective biological pest controllers.
How Many Aphids Does a Ladybird Eat?
A single adult 7-spot ladybird (Coccinella septempunctata) can consume up to 5,000 aphids during its lifetime. A ladybird larva — which looks like a small, spiny, dark-coloured grub — can eat approximately 300–400 aphids before it pupates. Given that a female ladybird can lay 200–1,000 eggs in a season, a single ladybird and her offspring can remove tens of thousands of aphids from your garden.
Ladybird Appetite by the Numbers
- Adult daily consumption: 20–50 aphids per day
- Larval daily consumption: 30–60 aphids per day
- Lifetime total (adult): Up to 5,000 aphids
- Eggs per female per season: 200–1,000
- Lifespan: 1–2 years
What Do Ladybirds Eat Besides Aphids?
While aphids are their primary prey, ladybirds also eat:
- Scale insects — sap-sucking pests found on ornamentals and fruit trees
- Mealybugs — white, waxy pests common on houseplants
- Spider mites — tiny pests that damage leaves
- Whiteflies — small flying sap-suckers
- Insect eggs — including those of other pest species
- Pollen and nectar — supplementary food when prey is scarce
UK Ladybird Species
The UK has 46 species of ladybird. The most commonly seen in gardens are:
| Species | Appearance | Diet |
|---|---|---|
| 7-Spot Ladybird | Red with 7 black spots | Aphid specialist |
| 2-Spot Ladybird | Red with 2 spots (variable) | Aphids |
| 14-Spot Ladybird | Yellow with black spots | Aphids |
| 22-Spot Ladybird | Yellow with 22 fine spots | Mildew (fungus feeder) |
| Harlequin Ladybird | Highly variable; 0–21 spots | Aphids (invasive species) |
Did you know? The harlequin ladybird (Harmonia axyridis), introduced to Europe for pest control, is now considered an invasive species. It outcompetes native ladybirds and can even eat their larvae.
How to Attract Ladybirds to Your Garden
- Tolerate some aphids. Ladybirds need a food source. Removing all aphids with pesticides eliminates the ladybirds' reason to stay.
- Plant pollen-rich flowers. Ladybirds supplement their diet with pollen and nectar. Good choices include fennel, dill, yarrow, marigolds, and calendula.
- Provide overwintering habitat. Leave leaf litter, log piles, and dense hedgerows where ladybirds can hibernate through winter.
- Avoid broad-spectrum pesticides. Chemical sprays kill ladybirds alongside pests. If you must treat, use targeted organic methods.
- Build or buy a bug hotel. Ladybirds will use hollow stems and crevices in a bug hotel for shelter.
Ladybird Life Cycle in the Garden
Ladybirds emerge from hibernation in spring (March–April) and begin feeding on early-season aphids. After mating, females lay clusters of bright yellow eggs on the underside of leaves near aphid colonies. The larvae hatch within a week and immediately begin hunting aphids. After 3–4 weeks of feeding, larvae pupate on leaves or stems, and new adults emerge after about 7–10 days.
Key Takeaway
Ladybirds are among the most valuable garden allies. A single ladybird family can eliminate thousands of aphids in one season. The best way to benefit from their pest control is to create a welcoming habitat: avoid pesticides, plant diverse flowers, and tolerate a small number of aphids as food supply.