There are many caterpillars found in gardens. They are the larval (immature) life stage of butterflies or moths. All feed on foliage, stems, flowers or fruit but not all are considered pests.
Many turn into attractive and beneficial butterflies or moths without doing severe damage to plants. However, some caterpillars are pests that destroy plants, and can ruin crops, especially small plants and seedlings. For example, budworms are a pest caterpillar that bores into sweet corn cobs while cabbage white butterfly larvae are small green caterpillars that attack brassicas such as broccoli and cabbage. Lily caterpillars attack lillies, clivias, hippeastrums and a range of other bulb species.
There are also caterpillars that feed on lawns (such as armyworm). They can be found throughout the year but especially from spring to early autumn.
Control options include netting crops to prevent eggs being laid on susceptible plants and regularly inspecting plants and picking off and squashing caterpillars. There are many predators that feed on caterpillars including birds and predatory wasps.
Caterpillars can also be controlled with an environmental spray such as EarthCare Natural Pyrethrum insect spray. When spraying the foliage follow the direction on the back of the pack and spray both sides of the foliage. Repeat application maybe needed for further control. Remember not to spray when beneficial insects and bees are around. If they are not hurting the garden, it’s always a good idea to leave them within the garden.
A healthy garden can also help prevent pest infestation. If your plants are strong and healthy, they may be able to handle and reduce the stress of pests and diseases. Applying Seasol regularly every two weeks during the year can help them to cope with environmental stress. Keeping plants fed with fertilisers such as PowerFeed All Purpose including Natives, better watering and appropriate light exposure can also help build tougher plants.