To kill insects in a package that you intend to throw out, place the package in an oven at 125 to 140 F and heat for 30 minutes to fully penetrate the package. Other means of destroying the pests is to place the package in a freezer at -20 F for a week, or spray with an insecticide. Only then should you discard the infested package. This will keep the pest from spreading. There are several insecticides available to control larder beetles at home.
Some formulations contain pyrethrins, which kills insects on contact.
They give longer lasting effects. There is no need to spray walls, ceilings or floors because the insects usually hide in cracks and crevices, or in food packages. Purchasing an aerosol spray can with a small 5 inch extension tube is handy for getting insecticides into cracks or other tiny areas. A good job of vacuuming removes dust or debris from cracks or crevices, permitting better penetration of insecticides. The vacuum cleaner bag should be put into a plastic bag and sealed before disposal to prevent insects from spreading.