How to deal with a ladybug infestation in the garden

Ladybugs are often considered a boon to gardens, helping to control pests - but they can actually be as pesky as other outdoor pests and lethal to certain types of plants.

If you find yourself with a ladybug infestation on your hands, you may wonder what to do. These magical little creatures can be tyrannical when present in large numbers, so it pays to be armed with the facts:

Ladybugs as pest control - Ladybugs are the natural enemy of a variety of garden pests. They're excellent for combating aphids, and are capable of consuming up to 50 or 60 of them a day. They also power through other insects and larvae, including scales, mealy bugs, leaf hoppers and mites.

Types of ladybug - Four common types of ladybug (or ladybird) are found in different regions of Australia. The transverse ladybug, Coccinella transversalis, is found everywhere; the common spotted ladybug, Harmonia conformis, avoids the Northern Territory and Queensland; the variable ladybug, Coelophora inaequalis, is not found in South Australia, Victoria or Tasmania; and the tiny two-spotted ladybug, Diomus notescens, is found everywhere bar Western Australia and the Northern Territory.

Ladybugs as harmful pests - Ladybugs – namely the large, orange variety with 28 spots – can also be pests in the garden. They're particularly fond of tucking into tomato, potato and curcurbit (i.e. cucumber, squash, pumpkin, melon) plants and can ruin your best efforts to grow vegies at home.

Getting rid of ladybugs the chemical way - While it's not great for your garden, insecticide is an effective way to get rid of ladybug pests. Cypermethrin is a synthetic pyrethroid insecticide that is an active ingredient in products like Bugoff, Alphasip and Vanquish. Cypermethrin-based products generally stay active for a few weeks.

Using insecticidal soap to remove ladybugs - Another way to combat ladybugs is to use insecticidal soap. In the garden it can be used in the form of a spray. First remove any weeds that may harbour the ladybugs, plus as many of the bugs themselves as you can, then spray the area with the insecticidal soap spray.

Ladybug traps - In Australia, pheromone traps are generally used to trap fruit flies, but they are also sometimes used to trap ladybugs. A pheromone is a species-specific scent produced by the female insect in order to attract the male.

If you have a garden over-run with ladybirds or other pests, talk to a garden pest control expert in your area: