They are a sucking insect and can be destroyed by regular application of Malathion and Volck Oil. Remember June brings in the heat of summer. While trying to protect new leaves from the strong sun it is still necessary to allow at least a few hours of morning sun. Too much shade will encourage rampant green growth. Heat suggests more water care.
Care means avoiding overhead moisture on green leaves.
Care means deep and more frequent water penetration to avoid alkaline build-up. Care means more water at the root level to offset the faster moisture evaporation though the leaves. Root rot damage can be the result of being too kind. Test your trees. Touch the surface.