pesticides, and optimizing the quality of Bt formulations are the main concerns
regarding microbial control in Iran. Although Bt-based insecticides effectively
control the target insect species, they still have not significantly substituted the
application of chemical insecticides. Moosavi and Zare (2016) have comprehensively discussed the limitations of bio-insecticide application or applying microbial
control. The major restrictions are that the available commercial Bt products do not
target all major pests of strategic Iranian crops. These Bt products are not available in
all agricultural regions, the cost is high, farmers lack knowledge, and more importantly, chemical pesticides have a raid speed of action and in some cases chemicals
have greater effectiveness. Therefore, in the market, bio-insecticides cannot compete
with chemical insecticides. Moreover, the efficiency of microbial pesticides is not
stable, limited shelf-life and specific requirements for storage are other constraints
that restrict their application.
On the other hand, the proper application of Bt definitely leads to successful pest
management. Several parameters affect the efficiency of Bt-based insecticides and
subsequently change the result of pest control. As it has been previously mentioned,
the spores and crystals of Bt have to be ingested by the susceptible larvae to exert
toxicity. Therefore, the coincidence of applying Bt in the field and the emergence of
susceptible larvae is a critical factor directly affecting the efficiency of a Bt product.
The instability of Bt formulations under field conditions threatens their effectiveness.
Additives such as protectants, dispersants, surfactants, and attractants, are required
in Bt formulation for their success in biological control. The limited shelf-life is
another constraint that has been considered for Bt formulation. All of the mentioned
parameters affect the efficiency of biological control based on Bt.
Further, the difficulties of microbial pesticide registration has to be taken into
consideration. In general, the registration of microbial bio-pesticides is a time and
money consuming process, although attempts have been made in Iran to simplify the
process (Moosavi and Zare 2016). Development and mass production of
bio-insecticides receive less attention and inadequate financial support compared
to what is dedicated to chemical insecticides.
The development and application of Bt crops is another controversial issue. The
possible adverse effects of transgenic crops on human and other non-target organisms, and also the environmental potential risks of these genetically modified crops
have been the matter of debate for at least the last decade. It seems that it is necessary
to repeatedly shed light on the side effects of chemical insecticides and to raise the
question: does the application of chemicals as an alternative have less environmental
and health hazards compare to transgenic crops? Based on these challenges, GM
crops have not been commercially released in Iran yet. Therefore, more scientificbased studies including biosafety regulation, risk assessment, field experiments, and
regulatory considerations are needed (Salehi Jouzani 2012).
10 Progress on the Bacterium Bacillus thuringiensis and Its. . .
429
regarding microbial control in Iran. Although Bt-based insecticides effectively
control the target insect species, they still have not significantly substituted the
application of chemical insecticides. Moosavi and Zare (2016) have comprehensively discussed the limitations of bio-insecticide application or applying microbial
control. The major restrictions are that the available commercial Bt products do not
target all major pests of strategic Iranian crops. These Bt products are not available in
all agricultural regions, the cost is high, farmers lack knowledge, and more importantly, chemical pesticides have a raid speed of action and in some cases chemicals
have greater effectiveness. Therefore, in the market, bio-insecticides cannot compete
with chemical insecticides. Moreover, the efficiency of microbial pesticides is not
stable, limited shelf-life and specific requirements for storage are other constraints
that restrict their application.
On the other hand, the proper application of Bt definitely leads to successful pest
management. Several parameters affect the efficiency of Bt-based insecticides and
subsequently change the result of pest control. As it has been previously mentioned,
the spores and crystals of Bt have to be ingested by the susceptible larvae to exert
toxicity. Therefore, the coincidence of applying Bt in the field and the emergence of
susceptible larvae is a critical factor directly affecting the efficiency of a Bt product.
The instability of Bt formulations under field conditions threatens their effectiveness.
Additives such as protectants, dispersants, surfactants, and attractants, are required
in Bt formulation for their success in biological control. The limited shelf-life is
another constraint that has been considered for Bt formulation. All of the mentioned
parameters affect the efficiency of biological control based on Bt.
Further, the difficulties of microbial pesticide registration has to be taken into
consideration. In general, the registration of microbial bio-pesticides is a time and
money consuming process, although attempts have been made in Iran to simplify the
process (Moosavi and Zare 2016). Development and mass production of
bio-insecticides receive less attention and inadequate financial support compared
to what is dedicated to chemical insecticides.
The development and application of Bt crops is another controversial issue. The
possible adverse effects of transgenic crops on human and other non-target organisms, and also the environmental potential risks of these genetically modified crops
have been the matter of debate for at least the last decade. It seems that it is necessary
to repeatedly shed light on the side effects of chemical insecticides and to raise the
question: does the application of chemicals as an alternative have less environmental
and health hazards compare to transgenic crops? Based on these challenges, GM
crops have not been commercially released in Iran yet. Therefore, more scientificbased studies including biosafety regulation, risk assessment, field experiments, and
regulatory considerations are needed (Salehi Jouzani 2012).
10 Progress on the Bacterium Bacillus thuringiensis and Its. . .
429