The ornamental design for a holder for insulatively securing electric fence wire, as shown and described.
FIG. 1 is a perspective top and side view of a holder for insulatively securing electric fence wire, showing my new design;
FIG. 2 is a top view thereof;
FIG. 3 is a side view thereof taken in the direction of the arrows upon line 3—3 of FIG. 2;
FIG. 4 is a side view thereof taken in the direction of the arrows upon the line 4—4 of FIG. 2; and,
FIG. 5 is a reduced scale, environmental perspective view thereof with the broken line showing being for illustrative purposes only and forming no part of the claimed design.