Strains of Streptomyces and relevant uses thereof

A biologically pure culture of the micoorganism Streptomyces orientalis Y31014, or a mutant or variant thereof having the following characteristics:

• a) a yellow substrate mycelium with a yellowish white aerial mycelium in a culture medium selected from the group consisting of yeast extract-malt extract agar, oat meal agar, inorganic salt agar or glycerol asparagine agar;
• b) grows in a culture medium containing a sugar selected from the group consisting of D-glucose, D-xylose, D-fructose, L-arabinose, raffinose, D-mannitol, I-inositol and salicin;
• and
• c) is highly virulent to white flies at a dilution of 1:100 to 1:1000 of culture broth of said microorganism to water.