Phoenix Tropicals Gardening

[jrabinowitz]

Hi, I have 3 palo verde trees which I purchased as 24" boxes and planted in early spring in Socal. They flourished for some time and then in mid-summer I noticed one of the 3 trees had been completely defoliated. I found that the other trees were exhibiting some defoliation as well. I must have picked off close to 100 grey caterpillars ranging from tiny up to 2". I spoke to a local nursery who sold me 'systemic drench' for the soil/roots and 'triple action' as a spray for the branches/leaves. This seemed to kill everything at the time - the completely defoliated tree is still without leaves, and the pillars seem to be coming back on the other trees. Another local nursey told me to purchase something with ' IMIDACLOPRID' in it. I will continue to spray and drench the ground as needed. Does anyone know what these pillars are? Will my one defoliated tree grow the leaves back? Any information would be greatly apprecaited!