1. U.S. Department of Agriculture, SEA, FR, Agric. Environ. Quality Inst., Beltsville, Maryland 20705
2. U.S.D.A., SEA, FR, Boyden Entomology Laboratory, Riverside, California 92521
3. U.S.D.A., SEA, FR, Stored‐Product Insects Research Laboratory, Fresno, California 93727, U.S.A.