ees ae Doon a eae 
3 
MONTHLY LETTER OF THE BUREAU OF ENTOMOLOGY! 
UNITED STATES DEPARTMENT OF AGRICULTURE © ° =! ¥ = © 
~ 





1 Ti:.Se Deamnsnons of Ars 
Number 224 Activities for November ; December, 1932 
(Not for publication) r . 
renee rier een send naan ies Aen ale neste sstanennnsasasieuatiencttmsassiersse 
= - SS 
AID FOR PHOTOGRAPHERS 
It may be of interest to field workers to know that the second 
edition of Circular E-290, "Suggestions for the help of photographers at 
field stations of the Department of Agriculture," is now available and 
copies may be obtained through the usual channels. 
INSECTS AFFECTING MAN AND ANIMALS 
New headquarters for cattle-grub investigations.--The field head- 
quarters for cattle-grub investigations have been moved to Ames, Iowa, 
and the laboratories formerly maintained at Galesburg, Ill., under the 
direction of R. W. Wells, and at Fargo, N. Dak., under the direction of 
W. G. Bruce, have been discontinued. The new field laboratory will be un- 
der the general direction of Mr. Wells. The move was made in order to 
facilitate research on the cattle-grub problem. At Ames the members of 
the staff will be in close touch with the scientists of the Iowa State 
College and Experiment Station and will have the advantage of adequate 
library facilities. The laboratory (at 325 Walnut Avenue), formerly a 
farm house on the outskirts of town, is supplemented by several acres 
of land, thus providing ample facilities for the care of animals for ex- 
perimentation. The work in North Dakota has been largely for the pur- 
pose of determining the factors responsible for the comparative lack of 
cattle grubs in the valley of the Red River of the North. Mr. Bruce will 
continue investigations along the same line in eastern Colorado and other 
parts of the country. Mr. Wells has been conducting investigations of 
horse bots at Galesburg, in addition to the cattle-grub work, and will con- 
tinue these studies at Ames. The personnel of the new laboratory also 
includes E. F. Knipling. 

Eggs of horse botfly tested for viability.--Mr. Wells reports that 
"Eees of Gastrophilus intestinalis DeG. were taken from five horses at 
Ames on November 26, to determine what percentage were still viable." 
It was found that from 28 to 70 per cent of the eggs had hatched; from 
7 to 16.4 per cent were dead; from 19.16 to 62 per cent were alive; 
and from 1 to 8.33 per cent were uncertain. "* * * many of the viable 
eggs are only partially incubated, due possibly to the cold weather. He 
will be interesting to note how long ‘and through what weather, on the 
host, viable eggs partially incubated, as well as those fully incubated, 
will survive." 
7 1422 + 
Wirnit 1 Perere, vA 
