19 
the larval and adult conditions upon grain; and furthermore, that were 
the insect more prolific it would become a source of much damage tc 
seed stock from its habit of devouring the embryo, or germ, going from 
kernel to kernel and destroying for germinating purposes many more 
seeds than it consumes. Both larvee and beetles serve a good purpose 
by attacking and destroying whatever other grain insects they happen to 
encounter. 
PARASITIC AND OTHER NATURAL ENEMIES. 
It might be supposed that insects which live a retired indoor exist- 
ence would be comparatively free from parasitic and other enemies, but 
such is not the case. 
It has been estimated of the granary weevil that one pair in the 
course of a year would produce 6,000 descendants. The moths are still 
more prolific, and as there are six or more broods of some species annu- 
ally it will be seen that if all the eggs of one individual and her 
offspring develop there would be produced in one year a whole myriad 
of the insects, sufficient to destroy many tons of grain. 
Fortunately, there are several natural checks to the undue increase 
of these insects. One of them is a diminutive mite which preys upon 
various species. Spiders that inhabit mills and granaries entrap the 
moths, and in the tield they are preyed upon by nocturnal insects as 
well as by birds and bats. 
The grain weevils and the Angoumois moth are often parasitized, two 
or three species of chalcis flies having been recognized as the enemies 
of each. The flour and meal moths each have several parasites, and 
most other granary insects are known to have either parasitic or pre- 
daceous enemies. 
The good work that is sometimes done by parasites in limiting the 
multiplication of their grain-feeding hosts is exemplified in a case cited 
of the Mediterranean flour moth having been destroyed by a parasite 
when other means had failed to dislodge it in the warehouses which it 
had invaded. 
METHODS OF CONTROL. 
The measures to be employed in the control of insects affecting 
stored products are both preventive and insecticidal. As an insee- 
ticide nothing answers the purpose so well as the bisulphide of carbon, 
which is a nearly perfect remedy against all insects that infest the 
storehouse. The remedies that will be discussed in the present circular; 
while intended primarily for use against insects in stored grain, have 
an almost equal value against all forms of animal life that oceur in 
products that are dried and kept in storage. 
PREVENTIVE MEASURES. 
A limited number of insects, like the Angoumois grain moth in the 
extreme South, enter the grain in the field, and certain precautions are 
therefore necessary to prevent their access to the granary. This is 
