Caterpillars are the larvae of butterflies and moths and can cause severe damage to plants.
Identify the problem
There are many types of caterpillars, which are the larval stage of moths or butterflies. The butterflies and moths usually lay their eggs on the underside of the leaves of plants that their young will feed on when they hatch.
Most caterpillars can be found throughout the year but are more prevalent during summer and autumn when the weather is warmer.
Caterpillars can cause severe damage to plants. Many, like the caterpillars of white butterfly, can be found in very large numbers and can strip affected plants to bare stalks in a few days. The sooner you see them, the easier it is to prevent damage. White butterfly, sometimes known as cabbage white butterfly, caterpillars cause severe damage to brassica vegetables such as cabbage, sprouts and cauliflowers. The caterpillars can reduce the vegetables to a collection of leaf skeletons in a short period.
To get rid of caterpillars follow these steps:
- We recommend spraying with Organic Caterpillar BioControl (naturally occurring soil bacterium Bacillus thuringiensis kurstaki or Btk). Beneficial insects such as ladybirds and bees are not harmed when using this BioGro certified organic product and there is no withholding period.
- Contact insecticides such as Organic Insect Control are suitable alternatives for use on crops. Please check on pack for withholding periods.
- On non-crop plants, a systemic insecticide like PLANThealth Spectrum can be used.
Did You Know
- Armyworm and greasy cutworm are the caterpillars of moths. These caterpillars eat through the stems of seedlings and lawns.
- The armyworm's diet comprises mainly of grasses and some small grain crops. When Army worms feed on the foliage and shoots of grass they leave bare patches. An infestation can be hard to detect as the caterpillars migrate to new feeding areas in the cool of the night. When the caterpillars near pupation, they can devastate an entire crop in a few days. The parent moth rarely does any damage and is not often seen as they mainly fly at night. These 45mm-long, greeny-brown grubs hide in the lawn thatch during the day. Look for small moths over your lawn at dusk. These are the adult army worms mating and laying eggs.
- Cutworms such as greasy cutworms chew the stems of young plants at night and hide in the soil around the base of the attacked plant during the day. They climb up stems and chew large holes in leaves of a wide variety of garden plants.
- Organic Caterpillar BioControl - The active ingredient in this product is Bacillus thuringiensis kurstaki (Btk) which is a naturally occurring soil bacterium. When ingested by the larvae of insects (caterpillars) it is activated in the caterpillar's alkaline gut where it produces a toxin that is lethal to the caterpillar. In the acid guts of other animals it is destroyed and is totally harmless. Btk is both safe, with no withholding period on crops, and highly effective.
- Butterflies and moths are members of the order Lepidoptera.