SHUCK PROTECTION FOR EAR CORN. SS 
Ears were classified as having good shucks if the shucks extended 
beyond the tip of the ear and closed more or less tightly about the 
silks. Most of the so-called good shucks were not ideal or such 
as would be the breeder’s aim, but were only Petter than those 
classed as poor shucks. 
If a hole or holes had been cut through a ee shuck by a 
worm, the ear was put in the class of good shucks with worm- 
holes; if no such openings had been made, the ear was classified 
as good shucks without wormholes. Only such wormholes as 
were cut through the shucks were considered. It was found, after 
removing the shucks, that some of the ears in the class good shucks 
without wormholes had been attacked by worms, too. They had 
entered through the silk channel and had either left through the 
same channel or died. 
While the shucks were being removed an examination was made 
for the work of the earworm and for insect infestation, mold, and 
discoloration. The number of ears infested with insects or damaged 
by molds and discoloration was thus determined for each class of 
shuck covering. 
At the time the notes were taken the earworms (Heliothis obsoleta 
Fab.) had completed their work. The black weevils (fig. 1) anda 
group composed of two or more species of small reddish brown beetles 
(fig. 2) were practically all the insects which infested the ears at that 
time. In this bulletin the black weevils are therefore termed 
““weevils’’ and the small reddish brown beetles are termed “beetles.”’ 
In making counts an ear was considered infested when only a 
single insect was found inside the shuck covering. 
Practically without exception ears infested with weevils were also 
infested with beetles. For this reason the number of ears infested 
with beetles is the same as the total number of ears infested with © 
insects. : 
The results of the investigations of the relation of the shuck cover- 
ing to insect infestation are summarized in Table I. 
TABLE I.—Relation of the shuck covering of corn to insect infestation in the field. 
Percentage of ears— 
Kind of shuck covering. Ineach | Infested with— 
‘| class of 
shucks. 
Weevils. | Beetles. 
ROO Tae hea Na aah Soli ps SOY tree ey gs An ot kee oe a 48 52 96 
KG OOC VAL MEVOnINOL OSs came os se eae eae Si eee eg ee Se 28 38 93 
Good, MAHOU WORMINO LOS tens Bae ree ae Seana iG ne ees is Se 25 9 56 
