Contents - Faperta

Genetic Engineering of Entomopathogenic Microbes for Pest Management 277
effi ciency to control the pest populations or increase their ability to survive under natural
conditions. Chemical agents do not have the ability to survive and reproduce under natural
conditions, while the biological control agents have. Therefore, the risk assessment for
biological control agents has to be different from that of synthetic pesticides (WHO, 1973;
FAO, 1986). The biological control agents have the ability to disperse on a large scale, can
be subjected to drift, subsequent regrowth, and secondary spread (Levin, 1995). Potential
for interaction between the released organisms and the environment have been discussed
by several scientists (Kalmakoff and Miles, 1980; Stozky and Babich, 1984; Fry and Day,
1990). Attributes of major concern in risk assessment are:
• Nature of genetic alteration;
• Phenotype of the wild-type organism;
• Phenotype of the genetically engineered organism; and
• Interaction with the environment.
Each of these attributes needs to be properly defi ned as determined by the knowledge
available and the inherent characteristics of the attribute. Genetic alteration includes stability
and characteristics of the DNA added, nature of alteration (addition, deletion, etc.),
the vector, and the RNA or DNA, which remains in the altered genome. Phenotype includes
the level of domestication, ease of control, pest status, range, and prevalence of gene
exchange for the wild-type organism and infectivity, changes in the utilization of substrate,
diseases and natural enemies, susceptibility to antibiotics, environmental adaptation, and
similarity to the previously released altered organisms. Change in the limits of adaptation
to the environmental conditions requires closer scrutiny. Detailed information about the
product, toxicology, anticipated and known effects on nontarget organisms, infectivity to
vertebrates, and hazard assessment are important components for risk assessment. It should
provide information on all aspects of the organism, possible interactions with the environment
at the test site, long-term effects, genetic exchange, containment, and monitoring.
Information about cultural and economic impact will play a major role in decision making
about the testing and release of genetically modifi ed microbes for pest management.
In most countries, the requirements for registration of genetically modifi ed microbial
pesticides include product analysis (product identity, manufacturing process, physical
and chemical properties, and the adjuvants), toxicology (acute toxicity, chronic effects,
hypersensitivity, oncogenicity, and reproductive effects), and effects on nontarget organisms
(nontarget plants and insects, aquatic and wildlife organisms, and human beings)
(WHO, 1973; FAO, 1986). Data for hazard assessment includes testing procedures (dosageresponse
curve, and maximum dosage used if positive results are obtained), and effects
on different nontarget organisms (birds, dietary effects on avians, acute toxicity to fi sh,
nontarget plants and insects, honeybees, and freshwater and estuarine invertebrates). For
assessing the exposure risks, the data should include biological fate of the gene (habitat,
survival, replication, gene fl ow, gene construct, probability of gene transfer and expression,
and expression level), and chemical fate of the gene (fate of the gene or gene product in
soil and water). Protocols should be established to generate data, and assure quality and
reliability of the data. Bioassays about the product, its toxicology and effects on nontarget
organisms, environmental conditions, and performance (including limitations) need to
be properly described.
There are serious impediments to the commercial deployment of recombinant NPVs.
Cost-effective means of mass production and in vivo production for rapid-action NPVs is