The causal agent was transmitted by Nephotettix nigropictus after an incubation of two weeks.
Polyhedral particles of 65 nm diameter in the cytoplasm of phloem cells were always associated with the disease.
Insect galls are the highly distinctive plant structures formed by some herbivorous insects as their own microhabitats.
In order to form galls, the insects must take advantage of the time when plant cell division occurs quickly: the growing season, usually spring in temperate climates, but which is extended in the tropics.
The meristems, where plant cell division occurs, are the usual sites of galls, though insect galls can be found on other parts of the plant, such as the leaves, stalks, branches, buds, roots, and even flowers and fruits.
They are plant tissue which is controlled by the insect.
Galls act as both the habitat and food source for the maker of the gall.