Pecan Nut Casebearer

Pecan growers and homeowners with backyard trees can rest easy for a couple more weeks.  The need for spraying the 1^st generation pecan nut talebearer has past and we did not see much of a problem.  This once again seems to be another result of the drought of 2011.  However pecan specialists do seem to think that we need to be on the lookout for the 2^nd generation of the pecan nut casebearer.  The pecan nut casebearer is a perennial pest that can significantly damage a pecan crop if not controlled.

            The PNC (Pecan Nut Casebearer) came early this year according to reports from South Texas, thankfully populations were not significant in the first generation.  Insecticide spray dates are determined by the PNC moth flight that starts in the south and moves north. The second generation moth flight will usually move fairly quickly, so they should soon be arriving in Wise County the second or third week of June.  Based on Extension Entomologist’s historical predictions the second generation of pecan nut casebearers generally will come 35-40 days following the first moth flight.  This would most likely put the possible spray dates around June 16-23.  If you would prefer to spray according to the egg lay on your particular trees and to determine if spraying is necessary, check pecan clusters for eggs and nut entries on a daily basis.  Eggs are usually found on the tips of nutlets and are about the size of the end of a ball point pen.  The eggs are white when first laid, and then turn pink to red over a three to five day period before hatching.

            Apply an insecticide the third day after the first eggs hatch to kill the larvae before they enter the nutlets.  Since larvae will be hatching over a week-long period or more, a second spraying may be necessary.

            Suggested insecticides for homeowners include:  Bt which has been effective in several tests and when timed accurately will not harm beneficial insects, also sprays containing Spinosad, Malathion and Sevin.  Suggested insecticides for commercial growers include:  Bt, Lorsban, Sevin, Imidan, Confirm 2F, Intrepid and Malathion.  The Bt, Sevin and Malathion would be better choices if livestock are grazing in the orchard.

            Follow label directions when using pesticides.

For more information concerning the movement of the PNC in Texas you can follow it through http://pecanipmpipe.org/ and you can go to http://pecan.ipmpipe.org/pesticidelist/resultsall.cfm for a list of products and see the attachments for other products to use.

And as always if you have any questions or concerns please contact the Extension office 940-627-3341