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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
growers noted the same phenomenon. 2 A study of the situation re¬ 
vealed the fact that the peas were heavily infested with the Southern 
Green Soldier Bug, Nezara viridula Linn., and that these bugs were also 
present to some extent on the pecans. These observations together with 
the fact that thin shelled varieties with plump meats were more subject 
to the trouble than were those which had thick shells, led to the thought 
that there might be a connection between the insect and the “disease.” 
In 1917, the writer conducted a few preliminary experiments, caging 
the bugs on clusters of seedling nuts. While far from being conclusive 
these experiments indicated very strongly that the suggested relation¬ 
ship was an actual one. There was no indication, however, as to whether 
the spot was an injury due directly to the insect or the insect acted as 
the carrier of a disease. 3 
In 1921 Demaree conducted a much more extensive experiment 
along similar lines. He attacked the problem from the pathologist’s 
standpoint, his main purpose being to determine, in case the suggested 
relationship was confirmed, if the actual cause of the trouble was a 
disease or simply an injury directly due to the bug. Demaree’s work 
showed conclusively that kernel spot is caused by the feeding of Nezara 
viridula, this feeding resulting in the extraction of all liquid from a 
hemispherical area centering about the point of attack, with a resultant 
collapse of the cells affected; and that no fungus or bacterial organism 
is concerned in the trouble. 4 
During the past season experiments have been undertaken to clear up 
several other points with regard to the relationship of the insect to the 
spot. For this series, some hundred cages were put in place during the 
second week in August. The varieties of pecan used were Frotscher 
and Teche; these varieties being chosen for reasons of accessibility 
altho they are not as subject to kernel spot, under normal conditions, as 
are many others. 
Commencing on August 21, five adults of IS! ezara viridula were placed 
in each of 10 cages an.d left for a period of about 10 days. They were 
then removed and other insects were placed in 10 more cages. This 
process was followed throughout the season till harvest time. The 
cages were not removed until the nuts were gathered. In each case, 
when insects were introduced into cages, nuts were cut and photographed 
2 Credit for the first observation of this apparent correlation belongs to J. B. 
Wight, a pioneer grower of budded pecans, of Cairo, Ga. 
3 Turner, William F., 1918. Nezara viridula and kernel spot of pecan. In 
Science n. s., V. 47, No. 1220, pp. 490-491. 
4 Demaree, J. B., 1922, Kernel spot of the pecan, and its cause. U. S. Depart¬ 
ment Agr. Bui. 1102. 
