Cabbage White, Large White, Large Cabbage White Butterfly , Grootkoolvlinder (Afr.)
This White Butterfly is a common garden visitor, however, they're not a very popular one. They're renown pests of members of the brassica family (Brassicaceae). Yellow eggs are laid in clusters on the leaves of cabbages, with caterpillars beginning to feast soon after hatching. Adult butterflies are in flight from April, all the way through to October. They're most active in summer, giving them the name summer snowflakes! They are migratory insects; one of the main reasons for their widespread distribution. They thrive in open habitats such as agricultural land, parks and gardens; particularly those containing Brassicas! Adults are attracted to nectar-rich flowering plants, such as butterfly bush and thistles.
A frequent garden resident that will eat and damage Brassica plants.
There's an abundance of solitary wasps which predate them.
Adult: Mature butterflies are white with black tips on the forewings. The underside of the hindwings is pale green which acts as camouflage when the butterfly is at rest. Females possess a large black spot on the hindwings, which is missing or significantly reduced in males. Larvae: Caterpillars possess irregular black spots which cover the body. Heads and rears are also black. If you can get close enough, it's possible to see long wispy white hairs. Pupae: The cocoons are whiteish-grey with black spots and yellow markings. They're sometimes seen on walls and fences. Eggs: Yellow and are laid on leaves of the host plant. Laid in clusters of 10- 20.
Young caterpillars feed in groups where older larvae feed individually. Leave holes in foliage. Foliage may be stripped completely. Caterpillars burrow into the hearts of cabbages.
By checking your Brassicas regularly, you should be able to detect any caterpillars before they cause too much damage. The best is to look when adult butterflies fly consistently over as it might be an indication that they are trying to lay eggs. Cabbages can be covered with netting to prevent eggs from being laid on the plants. Other barriers include diatomaceous earth, wood shavings or crushed eggshells. These insects are heavily preyed upon by other garden wildlife, including reptiles, mammals, birds and other insects. Attract natural predators to your garden by providing refuge spots. These can include anything from strips of native grasses, wildflowers, hanging baskets, climbers, or old bits of log/ deadwood. They're also heavily parasitized by wasps, which will insert eggs into the egg, caterpillar and pupal stage. Pteromalus puparum, braconids, ichneumonids, eulophids, encyrtids, pteromalids and chalcidids will all use this species as a host for their offspring.
More persistent insecticides include lambda-cyhalothrin, deltamethrin or cypermethrin. It's advised to always read and follow labels for chemical treatment thoroughly, as such chemicals are non-specific and can harm wildlife which was not intended to be targeted. Plants that intended to be eaten should not be sprayed unless stated on the pesticide label. Likewise, plants that are in flower should not be sprayed as this can harm pollinating insects.
Predated by many species of parasitic wasps and flies.