Hi,

My colocasias (specifically illusory, black stem and a generic walmart variety) have white patches on their leaves. Closer examination shows that the white patches are made of lots of white spotting. As the leaves age the patches grow and destroy the leaf. However my Persian palm alocasia and another unnamed alocasia are not affected by this disease. This disease is destroying the colocasias.

any help in tackling this disease would be much appreciated.

FYI I am located in Dallas Texas. All these plants get about 3 hours of direct sunlight. The newer leaves on the colocasias are getting progressively smaller.