v* •» 
INSECT PEST SURVEY BULLETIN 
Vol. 20 
Supplement to Number 1 
March g, 19^-0 
POPULATIONS OE CHINCH BUGS IN HIBERNATION 
NOVEMBEILDECEMBER, 1939 
Ev the Divio ion of Cereal end IVrag. . Inr.oct Inver tigations and 
the Division of Domestic Plant Quarantines 
Reports received from State entomological authorities and the staff of this 
Bureau late in the summer and_ in the fall of 1939 indicated that the chinch hug 
had become alarmingly abundant and was entering hibernation in great numbers in 
the North Central and in the southern Great Plains States. It was decided there- 
fore to discuss plans for a cooperative survey to determine as exactly as possib] 
the potent ial ' extent and density of the infestation as a basis of plans for a co- 
operative control campaign against the chinch bug should this become advisable in 
the spring of : 15)4o. 
A conference was called for this purpose at Des Moines, Iowa, on November g, 
1939* This was attended by representatives from State entomological agencies in 
Illinois, Iowa, Missoxiri, and Nebraska, as well as from the Federal Bureau of 
Entomology and Plant Quarantine, and resulted in plans for a cooperative survey 
to include all of parts of the following States: Illinois, Indiana, Iowa, Kansas 
Missouri, Nebraska, Ohio, and Oklahoma, A uniform procedure of sampling was 
agreed upon along lines proposed by C. M. Packard, of this Bureau, and modified 
to conform with local conditions of hibernation where necessary in the various 
States concerned. 
The sum of $10,000 was allotted ,by the Secretary of Agriculture from the 
appropriation provided under the general authorization for the Control of Incipi- 
ent and Emergency Outbreaks of Insect Pests and Diseases, to defray the expense 
of the proposed survey. It ’"as conducted in close cooperation with the entomolo- 
gists of the State experiment station and under the supervision of W, E. Dove, 
of the Bureau of Entomology and Plant Quarantine, with H. T. Rainwater as his 
assistant .and Philip Luginbill and C. Benton as technical advisers. The survey 
was begun on November S, 1939, and was terminated on December 15 . 
A total of 4,76l samples’ was taken in 432 counties of the g States, or an 
average of 11 sample" per county. In most of the area the individual samples con- 
sisted of l/5 square foot of big or little bluestem bunchgrass. In some States, 
however, complete bunches of the medium were taken and their area measured, and 
other suitable media, such as broomsadge or timothy, were substituted where 
necessary. The numbers of bugs per square foot in these samples were determined 
or estimated as closely as possible by tearing the samples apart ani sifting them 
or by means of a modified Berlese funnel. The populations per square foot of 
hibernation medium were averaged by counties and these averages, together with 
figures on acreages of susceptible crops in the respective counties, were used 
as a basis for making estimates of maximum potential needs for creosote barriers. 
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