The ornamental design for the end cap for a pillar-type insect trap, as shown and described.
FIG. 1 is an environmental view of an end cap for a pillar-type insect trap in accordance with the present design;
FIG. 2 is an upper perspective view of the end cap for a pillar-type insect trap shown in FIG. 1;
FIG. 3 is a lower perspective view of the end cap for a pillar-type insect trap shown in FIG. 1;
FIG. 4 is a top plan view of the end cap for a pillar-type insect trap shown in FIG. 1;
FIG. 5 is a bottom plan view of the end cap for a pillar-type insect trap shown in FIG. 1;
FIG. 6 is a front view of the end cap for a pillar-type insect trap shown in FIG. 1, which due to symmetry is the same as the back view; and,
FIG. 7 is a left side view of the end cap for a pillar-type insect trap shown in FIG. 1, which due to symmetry is the same as the right side view.
The broken line showing of a pillar-type insect trap is for the purpose of illustrating environmental structure and forms no part of the claimed design.