What’s complicated about the disease is its detection and treatment. The glaring symptom is the inability for the fruit to change color from green to orange; other symptoms include clogged vessels, a sour taste, brown seeds etc. The symptoms may be confused with a mineral deficiency like the one caused by zinc for example, which does not allow the fruit to change color either. The organism that causes it is a bacterium belonging to a category of bacteria termed “candidatus” (from candidates, incidentally). What makes these bacteria complicated is the fact that they are obligate pathogens and cannot be isolated - i.e. they do not survive outside their hosts, thus making it difficult to study them and hence, finding a cure. So the only solution to the problem at hand is to cut the whole tree before it infects other trees. Its like malaria, pre-quinine discovery.
What makes the disease more dangerous is that it can spread rapidly if the vector is not controlled. To get rid of malaria we target mosquitoes. In much the same way, to save oranges from citrus greening we target the vector which in this case is an insect called Asiatic citrus psyllid. The vector has natural enemies in wasps and ladybird beetles that lay eggs on top of the psyllid eggs by rupturing them so that once their babies hatch they can use psyllid eggs for food. Since the similarities are irrefutable, citrus greening might as well be called citrus malaria.
Research revealing the link between citrus greening and the psyllid was carried out by Dr. Shahid Chohan at the Department of Biosciences at the COMSATS Institute of Information Technology.