Leucaena leucocephala is the most exploitedmemberof the Leucaena genus for animal feed, as the leaves contain high crude
protein (CP) content ranging from 20 to 30% and are highly digestible (Brewbaker, 1987). This ‘giant’ Leucaena was widely
used as protein supplement in animal feed until the first outbreak of the Leucaena psyllid, Heterosylla cubana Crawford,
which occurred in Florida in 1983. This pest which highly preferred to feed on L. leucocephala was later discovered in
Hawaii in 1984 (Sorensson and Brewbaker, 1987) and subsequently caused devastating defoliation to Leucaena plants in
the Asia Pacific region. After several generations of crossing and selection between L. leucocephala and L. diversifolia for acid
tolerant and adaptability to high soil aluminum, resulted in the release of two hybrids, namely 40-1-18 Leucaena-hybrid