June 14, 1924 
Effect of Fumigation 
1105 
but three previously published records in American entomological literature 
containing reference to high temperatures caused by grain-infesting insects. 
Dr. L. O. Howard, in 1888, records (3) the sending to the then Division of 
Entomology by Judge Lawrence Johnson at Holly Springs, Miss., of seeds of 
Dolichos species badly infested with Bruchus scutellaris . These seeds had been 
stored in a paper sack of a gallon capacity, filling it about one-third full. With 
the temperature of the air surrounding the bag standing at 71° F., a thermometer 
placed in the seeds recorded 96° F. The difference of 25° F. was thought to 
be due in great part to a mechanical cause—the gnawing of the peas by the 
beetles and their larvae. 
W. D. Richardson, of Frederick, Va., in a letter of November 1, 1891, addressed 
to Dr. E. A. Schwarz and published in “Insect Life” (5), states that on August 
13, he had occasion to move a bag of peas which had stood in a corner of a room 
in his house for a month or more, and from which thousands of Bruchus scutellaris 
had been emerging. On touching the bag he was surprised at the temperature, 
and discovered that while the temperature of the room was 70° F., that within 
the sack of peas registered 88° F. This temperature continued for about two 
weeks, when it commenced to fall and the beetles soon thereafter ceased to 
emerge. Prof. A. J. Cook stated in 1889 (4) that insects had been known to 
produce heat in grain, but gave no temperature records. 
Doran states (7) that in February, 1892, at the Maryland Agricultural College 
his attention was called to a bin of bran or middlings 12 feet long by 6 feet wide, 
which was badly infested with Silvanus ( Carthartus ) cassiae. He discovered 
that, with the room temperature at 53° F., the temperature of the bran taken 
about lJ^j feet below the surface ranged from 42° to 95° F. These extremes 
of 42° and 95° F. were obtained from spots in the bin not more than 3 feet 
apart. The temperature of 95° F. was confined to a small space not more than 
2 to 3 feet in diameter, and within this the beetles and their larvae were very 
numerous. He states that the bran was “perfectly dry with no indication of 
mold or ferment.” The lower temperature of 42° F,, or near that, was found in 
various places in the same bin and in the bins and sacks of bran stored in the 
same room. Doran took a sample of bran from the spot showing the highest 
temperature and found 1 pound of it to contain about 1,500 beetles. There' 
were 103 weevils in an ounce of bran, which gave an estimate of 1,648 beetles 
to the pound. As 100 of these beetles weighed 23 grains, those in a pound of 
bran were estimated to weigh about 345 or 350 grains, or about one-twentieth 
of the entire weight of the bran and insects combined. 
Lintner in 1893 wrote (8) that wheat in Montgomery County, Pa., in 1892, was 
so badly infested with the Angoumois grain moth that when sacked directly from 
the threshing machine it would heat overnight. In 1901, Dr. L. O. Howard 
stated ( 9) that this pest was so abundant in the 1900 crop in Pennsylvania, New 
Jersey, and Delaware wheat that the grain heated badly. Dr. F. H. Chittenden 
observed (10) that heating may be caused independently of the attack of insects, 
but an abundance of insects in stored cereals frequently causes such heating that 
the temperature of infested material may be increased 25° to 40° F. above the 
temperature of the surrounding air. In 1915 Newell in Texas wrote (12) of the 
heavy infestation of sudan grass seed by the Angoumois grain moth, the pecu¬ 
liarity of the infestation being the resulting heating of the infested seed. Back 
(16) in 1922 gave data on the heating of chick-peas infested with the four-spotted 
bean weevil. Heating of wheat as a result of infestation by Sitotroga cerealella f 
Sitophilus oryza } S. granarius f Tribolium confusum and Cryptolestes pusillus was 
noted by the writers as a common occurrence in farmers’ bins in Montgomery 
County, Md., during the winters of 1921-22 and 1922-23. 
