Xylella fastidiosa bacteria are rod shaped, 0,2 to 0,5 micrometers in diameter by 1 to 4 micrometers in length (above, 18,500X) with a thick cell wall showing grooves and ripples. They are known as fastidious because of the great difficulty in obtaining cultures in the simple, conventional growing media in laboratories. Reproduction is by binary fission, or simple division in halves (a, below, 40,000X). The process usually takes about 30 minutes, a bacteria generating more than a million individuals in 24 hours, theoretically. X. fastidiosa is affected by high temperatures and can be eliminated in propagation material by heat treatment at 45 to 52 degrees centigrade (113 to 126 degrees Fahrenheit)  for a few minutes up to 3 hours.

40000X