For the most part, the 1st summer generation of the pecan nut casebearer is the only generation of this insect that pecan growers worry about controlling. The first summer generation attacks pecans right after pollination, with a single larvae capable of destroying an entire cluster of nuts.
However, pecan nut casebearer produces 3 generations per year. In the photo at above, you can see a hole or pile of pecan nut casebearer frass at the base of each of these nuts. These nuts were attacked in mid-July by the second summer generation. Since the nuts are much larger in mid-July, it only takes one nut to satisfy the hunger of a casebearer larva. The second and third generations rarely cause economic levels of damage.
This year we are seeing more nut drop from second generation pecan nut casebearer than in the previous 2 summers. Could this be a foreshadowing of higher casebearer populations next May? We will need to keep a sharp look out and maybe round up some more volunteers for running pherome traps.