This bulletin is a contribution from

Bureau of Entomology L. O. Howard, _Chief_.

Stored-Product Insect Investigations E. A. Back, _Entomologist

in Charge_.

ADDITIONAL COPIES

OF THIS PUBLICATION HAY BE PROCURED FROM

THE SUPERINTENDENT OF DOCUMENTS

GOVERNMENT PRINTING OFFICE

WASHINGTON, D. C.

AT

Carpet Beetles and Their Control · 第 21 / 24 题