ABSTRACT
The feasibility of using genetically modified plants for insect control has been convincingly demonstrated by the expression of genes for Bacillus thuringiensis (Bt) proteins. These proteins have been demonstrated to provide control of several insect pests in different crops (Barton et al., 1987; Fischoff et al., 1987; Koziel et al., 1993; Perlak et al., 1990, 1993; Vaeck et al., 1987). There are however many other economically important insect pests which are not effectively controlled by known Bt proteins. Several strategies are available to discover new proteins for insect control. These strategies include directed screening of sources that were previously shown to yield insect control proteins and random screening of novel sources.
