In the USA, the main crop for ethanol production is maize and since 1997 genetic manipulation has increased the yield of maize per hectare from 7.5 to 9.0 Mt/ha which is above the increase expected by traditional plant breeding (McLaren, 2005). This has been achieved by engineering maize to be resistant to the European corn borer by inserting a gene from Bacillus thuringiensis (Bt) that codes for a protein with insecticide activity. Another example is the pollen beetle which is a pest affecting the pollen of rapeseed, the main European source of biodiesel. There are no natural plants resistant to this pest capable of breeding with rapeseed and so genetic manipu­lation was the only solution. Transgenic rapeseed plants have been produced carrying a pea lectin gene and the lectin was found to be toxic to the pollen beetle larvae. The pea lectin was placed under the control of a pollen-specific promoter so that the lectin is not present in the rest of the plant (Ahman et al., 2006).