Stored-Grain Pests. 5 
not more than three-sixteenths of an inch long, and often smaller. It 
has no wings under its wing covers and the thorax is well marked with 
longitudinal punctures, two characteristics that distinguish it from 
the closely related rice weevil, with which it is often found associated. 
The well-grown footless whitish grub or larva and the pupa are 
shown at a@ and 3, respectively, in figure 1. The granary weevil is 
one of the oldest known insect pests, is a universal feeder upon grains, 
and is cosmopolitan, having been carried by commerce to all parts of 
the world. It prefers a temperate climate and is more frequently 
found in the Northern States than in the South. 
Both adult and larva feed voraciously on a great variety of grains. 
The adult weevils may live for 10 or more months, and during this 
period each female may lay from 200 to 300 eggs. Before laying 
her eges the female bores a small hole in the grain berry with her 
snout. When this is made she turns about and lays in it an egg, 
which she then covers with a gelatinous fluid which seals the hole. 
The small white fleshy and legless grubs that hatch from the eggs 
burrow about inside the kernel. When full grown, the grub trans- 
forms to the pupa stage and then into the adult weevil. In warm 
summer weather the granary. weevil requires about four weeks to 
pass through the egg, larva, and pupa stages and emerge as an 
adult of the succeeding generation. The period of development may 
be prolonged greatly by cold weather. 
RICE OR BLACK WEEVIL? 
The rice or black weevil is a small snout-beetle which varies con- 
siderably in size but rarely measures more than one-eighth of an 
inch in length (figs. 2 and 3). It varies in color from reddish brown 
to nearly black and is usually marked on the back with four light 
reddish or yellowish spots. It closely resembles the granary weevil 
in form, but it has well-developed wings beneath its wing covers, 
differs in color and markings, and has the thorax densely pitted with 
round, instead of longitudinal punctures. Figure 2 gives a good 
impression of the appearance of the rice weevil and its earlier 
stages. 
This weevil has been known from early times. It is found in all 
parts of the world where grain is used and is one of the very worst 
pests in stored grain. It is particularly abundant in warm countries, 
where it breeds continuously and rapidly destroys all unprotected 
grain. Throughout the South it causes tremendous losses to corn 
(figs. 4, 5, 6, and 7) and is the commonest of the serious pests of 
commercial grain shipments. 
The adult weevil lives, on an average, four or five months, each 
female laying between 300 and 400 eggs during this period. The 
2Nitophilus oryza L. 
