Biological control is simply the use of one or more natural enemies to keep control of pest populations in the greenhouse and out in the garden as opposed to using chemicals or laboriously picking them off by hand. Over the next few weeks as things really start to warm up in the garden and greenhouse pests problems will start to become evident, so it's worth getting to grips with biological control options now so you can respond quickly to arising problems. If you aim to be environmentally friendly with your gardening, biological controls are one of the best allies you can call on in the fight against garden pests. If however you attack your pest problems with chemicals through a fear of insects this may not be the method for you ; but you should try it. None of the insects and pathogens introduced into gardens for pest control can harm you, your children or pets and in most cases will control problems even when the pest has built up a resistance to chemical controls. Once the control has done its job and the pest population falls it too will die off through lack of food. It may not even come to this, many predatory insects will turn cannibal once their food source disappears. There are three forms of biological control ; predatory insects that eat the pests, parasitic insects that lay eggs directly into the host pest, and pathogens that spread disease among the pest population. For example, adult ladybirds can be used in the greenhouse to control aphid problems. The larvae can be used outside to protect garden plants. As long as there is a food supply the larvae will hang around. Some biological controls are only suited to enclosed greenhouse conditions, without the extra heat they may not survive or they may simply fly off. Others will thrive outside. So get to grips with the different controls and have them in mind for when pest problems start to pop up in your garden this season.