not to confuse acid fuchsin with basic fuchsin, irtiich is entirely- 
different in its action and is not suitable for detecting weevil infes- 
tation in grain. Acid fuchsin and glacial acetic acid are relatively- 
inexpensive and may be obtained from any drug or chemical supply house* 
It is not necessary to prepare fresh solutions of acid fuchsin. 
Any desired quantity may be prepared at one time, stored, and used as 
needed without loss in efficiency. The same solution may also be used 
a niomber of times without losing its efficiency. If after prolonged 
usage the solution tends to become murky it should be discarded. 
The samples of grain to be tested should be placed in a suitable 
container, pr-eferably a shallow dish large enough to adequately hold the 
sample and solution. Enough of the solution should be used to cover the 
kernels con^jletely. The grain is left in this solution from 2 to 5 
minutes. If left in the solution for a longer period the kernels will 
absorb enough of the solution to color them slightly, thus making it more 
difficult to locate the egg-plugs. If the grain is permitted to soak in 
warm water for 5 minutes before being treated, less staining of the 
kernels results without impairing the staining of the egg-plug. The 
water should be poured off before the fuchsin solution is added. After 
the grain has been immersed in the fuchsin dye from 2 to 5 minutes pour 
off the dye and wash the grain in tap water xmtil all -the excess dye has 
been removed. It may then be examined under water or drained and spread 
on a glass plate or similar surface for examination. 
The acid fuchsin stains the gelatinous egg-plugs a deep cheriy red, 
vdiereas feeding punctures and mechanical injury are stained a light pink. 
The egg-plugs (fig.l) are about the si«e of an ordinary pin prick and are 
readily seen -with the naked eye, but the use of a reading glass is helpful 
in finding them. 
Besides staining the weevil egg-pli»g8, this dye will also stain 
weevil feeding injury, as well as entrance and exit holes of the lesser 
grain borer. These are stained a lighter color, however, and can therefore 
be easily differentiated from weevil egg-plugs. Mechanical injuries, as 
a result of -threshing and subsequent handling of Hie grain, -will also be 
stained. However, they may be easily distinguished from the egg-plugs by 
their shape, size, and lifter color. Insect feeding injuries are round 
and smooth in outline, while mechanical injuries are very irregular. Grain 
that has passed -through cleaning machinery, such as scourers and disk 
separators, prior to milling, frequently bears injuries that greatly 
resemble the feeding injuries of wee-vils and grain borers. It is practically 
impossible to differentiate -these two -types of injury. However, the miller 
who -wants to know -jrtiether the grain contains -weevil infestation can find 
-this out by using -the stain on seunples of -the grain before it is run through 
the cleaning machinery, thus avoiding any confusion in distinguishing 
weevil egg-plugs and weevil or grain borer feeding injuries from mechanical 
injuries. 
The proportion of weevil egg-plugs to feeding punc-tures -will depend 
largely upon (1) the number of adults to which the grain has been exposed; 
and (2) the condition of the grain, particularly as to mois-ture content. 
