The first gene to be successfully transferred to
another plant species resulting in enhanced insect
resistance was isolated from cowpea and encoded
the trypsin:trypsin inhibitor CpTI [35]. The
protein is an effective antimetabolite against a
range of field and storage pests [1]. Lepidoptera
and Diptera possess mainly serine proteinases and
the obtention of plants more resistant to Lepidoptera
through the use of serine PIs of different
origins has been reported (Table 2).