Types of plants that have caterpillar infestations
The types of plants that have caterpillar infestations include nasturtiums and all types of brassicas including cabbages, cauliflowers, sprouts and turnips. The photographs below show a caterpillar infestation on a nasturtium plant, and on a young cauliflower plant.
Large white butterflies lay clusters of yellow eggs as shown in the photograph below:
These eggs develop into slightly hairy yellow and black caterpillars, as shown in this photograph:
How to treat infestations
It is best to treat plants organically, without using pesticides. You should wear a pair of gloves to remove the caterpillars from the leaves. The gloves are necessary to protect you from being stung by the spines on some caterpillars. Drop the caterpillars into a bucket of soapy water containing washing-up liquid. This will drown the caterpillars. You can also cut off a leaf (that has eggs or caterpillars on it) from a plant that has plenty more leaves. There is a really easy way to remove the eggs from the leaves. Carefully wipe the eggs from the plant leaf using a dock leaf. You will find that the eggs stick to the dock leaf. Then you can throw the dock leaf onto the ground and squash it under your shoe to destroy the eggs.
Spray the plant with garlic solution
Spray the plant with garlic solution containing three crushed garlic cloves, one tablespoon of vegetable oil and one teaspoon of washing-up liquid in one litre of water. This will deter insects such as large white butterflies and other butterflies. You can use a pressure sprayer. For an example, click here. A spray gun similar to the one in the photograph below can also be used.
There are some excellent 5-litre pressure sprayers on Amazon. To purchase one on Amazon, click here. There are several products on Amazon that can be sprayed on plants to protect them from most insect pests, such as greenfly, blackfly, caterpillars, beetles, weevils, apple & pear suckers, sawfly, and whitefly. An excellent product to use is Provado Ultimate Fruit And Vegetable Bug Killer. Click here, to see this product on Amazon. It is not clear if this product is suitable for use in organic gardening. Another product on Amazon that is certified for use by organic growers is “Solabiol Bug Free”. To purchase this on Amazon, click here.