Arbortech Tree Service (512) 940-0705 Team of Certified Arborists, tree experts, and tree care of Austin since 1988 (TX-0189)   Tent Caterpillars Often referred to as web worms, these caterpillars devour the foliage of the host tree.  This infestation is addressed in the Spring with a micro-injection of Abacide. This application lasts throughout the growing season, thus controlling several potential generations.  This benign chemical is specific to chewing insects.  Spraying is also an option.  Although Pecan trees are their favorite target, other trees can be affected Spring Caterpillars Every year in the middle of March these caterpillars begin feeding on the foliage of Live Oaks and Spanish Oaks.  They can defoliate a tree in only a few days.  A properly timed spray can easily control these insects.  Waiting for symptoms to appear can often be too late.  Our insecticide is environmentally friendly and contains an added fungicide and foliar fertilizer. Spider Mites Spider mites are an occasional pest of Cedar trees (Juniper).  They are a sucking insect that causes browning of the needles in the summer.  Small webbing is also seen.  Heavy infestations can cause the whole tree to appear brown.  We use a biological control instead of insecticides, which also contains a fungicide to control the fungus Phomopsis that is seen in association with this pest. Aphids Aphids are soft-bodied insects that use their piercing sucking mouthparts to feed on the trees leaf sap.  They usually occur in colonies on the underside of tender terminal growth.  Heavily-infested leaves can wilt or turn yellow because of excessive sap removal.  Although the tree is likely to survive this attack, these insects are believed to be the main mechanism responsible for the spread of many bacterial and mycoplasmalike organism (MLOs) diseases.  A spring micro-injection gives season long control. Scale Scales are close relatives to aphids, but are more difficult to control.  This is because they are sessile (don't move).  This allows them to excrete an outer layer that protects them from the spraying of insecticides and from their would-be predators.  As a sucking insect, a micro-injection in the spring, when they first appear, is our best defense against these potential disease transferring insects.