Apparently the adult weevils feed on the endosperm of the grain kernel 
in the process of drilling the cavities in -which they lay their eggs. 
Thus, unless the weevils are disturbed, eggs are usually deposited in 
all cavities that the adults drill into the kernels. If the populations 
are very large many punctures that do not contain eggs may be found. 
This is because the female weevil was disturbed while drilling the egg 
cavity smd did not return to deposit the egg. The author does not con- 
sider this a significant factor, however, for in all such oases en- 
countered there were one or more egg-plugs in addition to the egg-free 
punctures. 
If the moisture content of the grain is con5)aratively low, that is 
11 percent or less, the female weevil may drill a cavity but, finding 
conditions unsuitable, will not deposit an egg. Such grain will generally 
have a comparatively high percentage of egg-free punctures. In nvunerous 
dissections of kernels that had been treated with this dye to locate the 
®6€"Pl^gs, weevil eggs were found under every plug. The female weevil 
does not seal the cavity in the kernel unless she has deposited an egg. 
By actual count the total hatch is from 85 to 90 percent of all eggs laid. 
With moisture and temperature conditions remaining favorable, all larvae 
that hatch will complete their development. 
Since this dye stains the weevil egg-plug, it is suitable for determi- 
ning weevil infestation in wheat, com, and sorghtnn grains. Fifteen va- 
rieties of hard and soft wheat have been tested, and on all of them the 
egg-plugs could be readily detected. Polished rice takes up too much 
stain to reveal egg-puncture plugs. The stain has not been tried on other 
grains, and its effect on the eggs of weevils that glue their eggs to the 
surfaces of dry beans and peas has not been determined. 
Weevil eggs may be readily distinguished from the eggs of other 
species of grain-infesting insects, because all other species lay their 
eggs loose among the kernels, in larger feeding cavities in the kernels 
or in floury material mixed with the grain. 
Correction Slip 
U. S. Euruau of Entomology and Plant Quaiantine ET-256 
The f:-ct that this is a repoit of a study made \ander the Research 
and Marketing Act of 19A^' was inadvertently omitted. 
Page 3, last paragi'aph — In place of first 3 lines, including 
that v'hich ends "Thi3 dye, commonly used as a," substitute the 
follov.dng: 
The other prepo ration that may be used is an 
iodine solution v;hich is prepared by diluting 20 ml. 
of Lugol's solution, obtainable from ony drug or 
chemical supply house, with v^atef to make a total 
\'olume of 900 ml. This preparation, commonly used ^ 
