Butterflies, especially the colourfully marked types are very pretty to watch as the undulate through the summer breezes but there are certain varieties that can cause losses in your vegetable garden.
The cabbage white butterfly
The main culprit is the cabbage white butterfly which is mostly attracted to a chemical emitted from the leaves of brassicas. The brassica group covers such vegetables as cabbage, brussel sprouts, broccoli and cauliflower. The butterfly lands on these plants and in itself is harmless but the eggs it deposits are the problem, or what eventually emerges from these eggs. Emerging quite soon after are the dreaded caterpillars which are hairy and about 3 to 4 cm long.
Caterpillars
Caterpillars are the larvae or the young of the butterfly; this is the main feeding and growth stage of the butterflies' life cycle. As most vegetable growers know caterpillars are very hungry and a small handful can turn a head of cabbage into a skeleton within a day or two. Infested leaves are quite toxic to animals and humans even if washed thoroughly.
Control methods
So how can you battle against the caterpillars, well there are various chemical and organic methods. The chemical methods are available in all good garden centres in the form of sprays, dusts and bug guns with names too numerous to mention. With cabbage, broccoli etc being food crops that you may grow at home organically to avoid chemicals you should try to tackle the menace organically. Cover your plants with sheer netting whilst the butterflies are around, if they cannot touch the plants then they cannot lay their eggs on them. Ensure the netting allows sufficient sunlight through to enable growth.
Companion plants
Try planting tomatoes and celery as companion plants close by as their scents tend to cancel out the scent emitted by brassicas therefore deterring cabbage white butterflies. Finally if all else fails try sending your cat or cats on holiday during the summer, you'll be surprised how many songbirds start to visit your garden. Songbirds just love caterpillars.