THE CADELLE 37 
ter in the vicinity of Washington, D. C. The larvae and adults, on 
the other hand, are very resistant to low temperatures and, pro- 
tected as they normally are in granaries and storehouses, are able 
to survive very cold weather. Both larvae and adults have survived 
exposure to a temperature of from 15° to 20° F. for a period of sev- 
eral weeks, and will even withstand a temperature of 0° F. for sev- 
eral hours without apparent injury. 
CONTROL MEASURES 
Cleanliness in the storehouse and granary is one of the most im- 
portant factors in control. The habit of the larvae of burrowing into 
wooden floors, partitions, and walls of bins, storehouses, and ships, 
accounts for much of the loss occasioned by fresh supplies becoming 
infested when placed in storage space formerly occupied by infested 
material. The substitution of concrete for wood whenever possible 
| is one of the best means of preventing the rapid infestation of fresh 
supplies. On farms where grain bins are usually constructed of 
wood, hardwood should be used in preference to soft wood, and the 
i construction made as tight as possible. Bins should be inspected 
annually and any badly burrowed woodwork removed. 
The cadelle in all stages can be killed by fumigation with carbon 
disulphide, from 6 to 8 pounds per thousand cubic feet of bin space 
being used where bins are tight. In loosely constructed bins even 20 
pounds per thousand cubic feet of space might not kill all cadelles 
in the grain and woodwork. Carbon tetrachloride, alone or in com- 
bination with ethyl acetate, has the advantage over carbon disulphide 
in that its vapor is nonexplosive and noninflammable, but it has the 
disadvantage of being about one-half to one-third as effective and 
must therefore be used in greater dosages. 
Hydrocyanic-acid gas is effective in killing all stages of the cadelle. 
It has the disadvantage, however, of not penetrating bulks of grain 
and flour sufficiently to reach all cadelles. For this reason the 
cadelle, along with other beetles found in flour mills, can be better 
killed by the use of heat, as shown by Dean (7). Since the cadelle 
is nearly always associated with other common grain pests, any 
treatment applied for the control of grain pests in general will be 
effective against the cadelle. 
SUMMARY 
The cadelle, Tenebroides mauritcmicus L., is a very common and 
destructive cosmopolitan pest of grains and grain products and was 
first described in 1758. It is usually associated in its attack upon 
food products with other grain pests. In the case of cartoned goods, 
such as breakfast foods, the economic importance of the cadelle is 
much enhanced by the holes it bores in the cartons, thus giving other 
and smaller pests avenues of attack upon foods that otherwise might 
remain immune from infestation. The cadelle prefers darkness and 
secretes itself in both larval and adult stages beneath any object or 
between sacks of flour or other containers of its food. It therefore 
is less often seen by the casual observer than other grain pests, even 
when rather abundant. Both adult and larva are restless feeders 
and consequently move about feeding here and there, preferring the 
