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TRUCK-CROP INSECT INVESTIGATIONS 
J. E. Graf, Senior Entomologist, in Charge 
The summer laboratory of the pea aphid project at Columbus, Wis., 
was opened on May 1. During the present season this project will include 
studies along ecological lines, and will be in charge of J. E. Dudley, Jr. 
W. H. White visited Norfolk, Va., Chadbourn, N. C., and Charleston, 
S. C., in the early part of May to observe the results of the spring con- 
trol methods against the seed corn maggot on potatoes, and to check over 
the plan of work on strawberry insects for the coming season. 
N. F. Howard visited Philadelphia, Pa., and vicinity, May 1 and 2, 
to study methods used in controlling the Japanese beetle by parasites and 
insecticides. 
On May 3 C. H. Griffith, of the Twin Falls, Idaho, sugar-beet 
leafhopper laboratory, established a temporary summer substation at Cor- 
vallis, .Oreg. 
C. 0. Bare, Sanford, Fla., visited Alhambra, Saticoy, Santa Ana, 
and other points in California in the latter half of May, to study methods 
of rearing parasites and predators on a large scale. 
Dr. Bernard Trouvelot, Professor of Entomology, National School 
of Horticulture, Versailles, France, who is studying parasites of the 
Colorado potato beetle, visited the Baton Rouge, La., laboratory, May 25, 
and collected some parasitized material for shipment to his rearing sta— 
tion at Geneva, N. Y. 
K. L. Cockerham, Biloxi, Miss., visited A. & M. College, Miss., 
May 29, to confer with Prof. R. W. Harned and other State officials re— 
garding the work on eradication of the sweet potato weevil. 
J. E. Dudley, Jr., Madison, Wis., has devised a method for check-— 
ing infestation counts of certain insects on some cereal and truck crops. 
The device consists of a box 20 inches long, 10 inches wide, and 14 inches 
high, equipped with a sliding bottom, faced with a knife edge. The box 
has adjustable legs to regulate the depth of cutting and thus insure 
comparable samples. When it:is desired to secure the insect population of 
peas or alfalfa, the bottom is opened, the box suddenly plunged into the 
selected spot in the field, and the bottom pulled shut by cables so rapid- 
ly that practically no insects escape. The knife edge cuts the plants as 
it progresses. A screen cylinder containing cyanide flakes is placed in 
the box immediately and the whole insect population is killed. This de-— 
vice is used for checking the relative infestations as secured with a net 
and the aphidozer. Any one interested in this method may obtain speci- 
fications by communicating with the U. S. Entomological Laboratory, R. 3, 
Columbus, Wis. 
