The red variety has matured before the imported cabbage worm population is high enough to cause damage. Quality of the green cabbage, however, with two weeks to go before maturity, will be reduced unless steps are taken to reduce worm numbers. Slugs are best dealt with by trapping. A slug trap can be made by simply filling a shallow saucer with beer, and placing it in the garden. White flies in homes and greenhouses can be trapped on yellow cards treated with a sticky material.
Pheromone traps are available commercially for some insect pests.
Pheromones are odorous chemicals produced by insects to communicate about danger, food sources, and sex. Physically remove the pest . The most common way of dealing with weeds is to hoe them out. Large and slow insects such as the tomato horn worm, can be removed by hand. Some creatures can be kept out by building a fence around your garden.