As agricultural production intensified over the past
few decades, growers became more and more dependent
on agrochemicals as a reliable method of crop protection.
However increased use of chemicals caused several
negative effects for example development of pathogen
resistance to applied chemicals and their non-target
environmental impacts. Moreover increasing cost of
pesticides, particularly in developing countries and search
for pesticide free food in developed countries has led to a
search for substitutes for these products. Moreover there
are many diseases in which chemical solutions are
ineffective. Biological control is thus being considered as
an alternative way of the chemical management in
agriculture. It is defined as the practice of using beneficial
natural organisms to attack and control harmful plant and
animal pests and weeds, called biological control