Wholeheartedly agree there. Can you reach the tops of the palms with a pump sprayer? It might take a few more repeat sprays, but if you're diligent, you'll get them.
My neighbor just recently was a pesticide inspector for the state (until someone offered him a job for twice the pay!). He says for this type of insect the systemics have been shown to actually advance the insects' tendency to develop resistance to the insecticides. Since the systemic is in the plant for sometimes a year, and the insects feed on it again and again, while most are killed, it only takes a few to survive to start up a new generation who are then resistant to that chemical.
He likes the "mechanical" means of killing these type of pests - soapy sprays and horticultural oils. The insects never get resistant to them!
