Question
Hi Rick,
Here is my problem. I live in the Mojave Desert, Palmdale, Ca. I have leland cyprus trees in my backyard. In the last couple of years in our area we have had problems with bore mites. Which have weakened the trees somewhat. I use cygon which helps fight the problem, use it in the spring and fall. About every 6 weeks I hit the trees with 16-16-16 ingredient to help give vitamins to the trees. All of a sudden this year I have ants all over the trees. What are they going after and are they possibly nesting in the tree? The trees are about 30 feet high. They are great for shade. I tried using that spray ingredient from LOWE"S for insects on trees and shrubs. I feel I am loosing this battle. Also, because of the bore mite problem, sap is extruding from the bark in numerous places.

Thanks,
Don Cramer  

Answer
i'm in southern NJ(zone 7-8).
it's been very wet this year in the mid-atlantic states.  much of the west has been in a drought situation. both can cause trees stress and to perform poorly. 1st - i'm not sure 16-16-16 is an appropriate fertilizer for leyland cypress. the percentages of N-P-K are very high.  apply a lower % NPK(3-2-1) evergreen fertilizer(i use hollytone by espoma) once in the spring and again in the fall. sprinkle 2-3 coffee cupfulls on the ground under each plant. the rain will do the rest. check w/a local garden center/nursery.
there is a disease(rust, canker, etc.) that attacks leyland cypress in particular. one way to prevent it is to only prune during dry weather. during wet weather it spreads faster. check the foliage on the effected tree for fungal or rust signs(hyphae fungal structures, powdery substance, presence of rust colored residue, etc.).
w/out seeing the trees it would be hard to diagnose the problem & give a solution to correct it.  check w/local garden centers/nurseries more familiar w/plants and pest in your area.  they should be able to recommend an appropriate pesticide for control of the pest. always follow the labeled directions for good results.
you could also check w/your local county agricultural extension service. i'm in NJ and would use Rutgers University Cook College county extension services. try any large university or college in your area(arizona state, Cal state, oregon state, etc.). you can locate them on the internet for information in your area. usually they have an email for questions.
ants normally don't harm trees. in fact they pollinate many species of plants. here in NJ i would be concerned whether they were carpenter ants or not. they would be a sign of dead wood in the tree caused by borers. in early spring you might want to spray the bark w/dormant oil(volck oil) to smother any eggcases on the bark.
you might want to call a local EPA/DEP licensed arborist to apply a stronger/safer pesticide to do the job. they have access to restricted use pesticides, not available to the public.
good luck
rick
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