Why they are a Pest
The beetles chew small holes in leaves giving them a lacy effect. They feed on a range of vegetable plants particularly cabbage, potatoes, spinach, herbs and seedlings, causing serious damage and on a large scale will completely destroy the leaves, especially on small leafed plants.
Even a small number of beetles on a plant will disfigure the leaf and this is not desirable on plants such as herbs and greens which are grown for their leaves. Some species have been introduced in Australia and North America to control weeds. In Australia the South American flea beetle Agasicles hygrophila was introduced to control alligator weed.