Large cabbage white butterfly
Large cabbage white butterfly, Cabbage white / Large white (Eng.), Grootkoolvlinder (Afr.)
The small cabbage white butterfly belongs to the same genus as the large cabbage white, namely because both use the same genera of plants as a host to lay their eggs. However, these butterflies cause less damage in comparison to their older relatives. This species is also a migrant, migrating from the British Isles to the continent to breed. Adults appear white with some form of black dotting on the forewings. Unlike the large white, these butterflies lay single yellow eggs beneath the host's leaves, as opposed to clusters.
Caterpillars will eat plants belonging to the brassica family, possibly making vegetables inedible.
Butterflies are nectar feeders and will pollinate plants as they feed. These plants include mustards, dandelion, red clover, asters, and mints.
Adult butterflies are white with black tips/ spots on the forewings. The underside of the hind wings is pale greenish which serves as camouflage when the butterfly is resting. The wingspan can reach 6cm. Larvae are bright green, with thin, faint yellow lines running longitudinally. There are also tiny black speckles that cover the whole body and yellow dots that run laterally down the body. Pupae are bright green, 'spiky', and look a bit like small packages made from leaves. Eggs are yellow and are laid individually underneath leaves.
Foliar damage as the caterpillars feed on the leaves. These caterpillars feed less aggressively in comparison to the large white caterpillars. However, larvae of the small white can bore within the hearts of vegetables, making them inedible. Wet, greenish-brown excrement can sometimes be seen on plants.
Europe, America, Northern Africa, and parts of Asia.
By checking your Brassicas regularly, you should be able to detect any caterpillars before they cause much damage. The best is to look for when the butterflies fly consistently over plants, as this indicates they are attempting to lay eggs. Caterpillars and eggs can then be hand-picked off and killed. Cabbages can be covered with netting to prevent eggs from being laid on the plants. Also, there are parasitic wasps that parasitise the pupae of this butterfly species. Some birds can eat these caterpillars too.
Insecticides such as fenvalerate are very successful for the control of cabbage white butterflies. Other insecticides such as deltamethrin, cypermethrin, malathion and fenitrothion can be used. On plants intended for eating, be sure the crop is listed on the pesticide label and follow the instructions carefully. If you decide to use persistent chemicals please research products carefully, or consult with your local garden centre.