There are different groups ofcrygenes that are
active against specific groups of insect pests:cry1 group againstLe-pidopteranpests andcry3groupagainstColeopteranpests . Efforts on the development
of insect resistant transgenic crops have been reviewed by many
authors .
Some of the specificcrygenes used so far include thecry1Abgene
against maize corn borer in maize ,
cry1Ab/cry1Ac genes against cotton bollworm in cotton and against stem borers in rice,
andcry3Agene against potato beetle in potato