LIBRA. 
UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1428 
Washington, D. C. 
October, 1926 
THE CADELLE 
By E. A. Back, Entomologist in Charge, and R. T. Cotton, Entomologist, 
Stored-Product Insect Investigations, Bureau of Entomology 
CONTENTS 
Page 
Origin and synonymy 1 
Common names 2 
Economic history 2 
Distribution 4 
Nature of injury- 5 
Life history and habits 13 
Seasonal history 32 
Page 
Technical description 33 
Resistance to starvation 36 
Resistance to low temperatures 36 
Control measures 37 
Summary 37 
Literature cited 39 
ORIGIN AND SYNONYMY 
The cadelle (Tenebroides mauritanicus Linne) is an important 
pest of grains and of grain products such as flours and milled break- 
fast foods. It belongs to an extensive family of beetles, nearly all of 
which are inhabitants of the New World. For this reason it has 
been thought by some to be native to America. The fact, however, 
that it alone of the genus Tenebroides has the habit of feeding upon 
grain or grain products — a habit that must have been acquired 
centuries ago — leads one to suspect that it may possibly be a native 
of the Old World, where the custom of storing grain for food was 
first established. Early English writers thought it had been in- 
troduced to England from Africa. At the time of its description 
in 1758 it had undoubtedly been carried by commerce to nearly 
all parts of the civilized world. 
In 1758 it was first described by Linne (20, p. 417) -, 1 who gave it 
the name of Teriebrio mauritanicus and classified it with the meal 
worm, Tenebrio molitor, which he described at the same time. 
Thirty-two years later, in 1790, Olivier (23, p. <21$) published a short 
account of this insect and proposed for it the generic name of Tro- 
gossite (from the Greek words TpwyfiT, to eat, and <tItos< grain). 
For many years thereafter it was known as Trogosita mauritamca 
and until recently the family of beetles to which it belongs was 
known as the Trogositidae. 2 
1 Numbers in italic in parentheses refer to " Literature cited.*' p. 30. 
2 The family was later known under the name of Temnochilidae and is now called the 
Ostomidae. 
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