Though plant health care focuses on organic and alternative means of dealing with insects and diseases.  Spraying is sometimes necessary to accomplish goals.  It is important to weigh the benefits against the repercussions of using chemicals.  All living things are part of a complex and delicately balanced system.  The removal of a single species or part of the system can have profound implications.  It can set off a chain reaction that could affect many other species and take years to recover from if at all.