The cabbage moth is common during dry cool seasons in many tropical and subtropical regions. It is an important pest in Kenya and Uganda.
|Damage caused by caterpillars of the cabbage moth(Crocidolomia binotalis)|
(c) A. M. Varela, icipe
Young caterpillars chew off top leaf surfaces. Older caterpillars feed under a web of silk on young leaves, petioles and growing points of the plant, often damaging it entirely, by eating most of the soft tissue leaving only the ticker veins (skeletonisation). In addition to the feeding damage, host plants are often completely soiled with excrement. On cabbage the caterpillars of the cabbage moth skeletonise the outer leaves and bore into the developing head filling it with frass and excrements. Damage in the cupping stage results in either aborted or multiple heads. They cause borehole damage with frass and excrements in the developing head. Even a single mature caterpillar per plant is capable of causing economic loss to cabbage at pre- and post-heading stages.
Caterpillars nibble on the growing tip of seedlings/transplants of cauliflower causing 'blindness'. They also cause skeletonisation of outer leaves after planting and discolouration of curd. Caterpillars damage pods and eat the seeds.
On mustard caterpillars cause extensive skeletonisation of leaves and webbing of leaves and inflorescences. They also bore holes in pods eating the seeds.
On kohlrabi caterpillars cause extensive skeletonisation of leaves.
The cabbage moth is primarily a pest of brassicas and is occasionally an important pest of cabbage. Economically important hosts are cabbage, cauliflower, Chinese cabbage, broccoli, kohlrabi, radish and mustard. Wild plants like thyme, steaved tree(Crataeva religiosa), an ornamental crop (Clerodendron fragranspeniflorum) and spider flower (Cleome gynandra) are found to harbour this pest. Cabbage moth has also been recorded feeding on cotton and pigeon pea.
Affected plant stages
Flowering stage, fruiting stage, seedling stage and vegetative growing stage.
Affected plant parts
Fruits/pods, growing points, inflorescence and leaves.
Symptoms by affected plant part
Fruits/pods: internal feeding; external feeding.
Growing points: external feeding.
Inflorescence: internal feeding; external feeding; webbing.
Leaves: external feeding; abnormal forms; internal feeding; webbing.