INSECT PEST SURVEY BULLETIN 
Vol. 20 Supplement to Number 4 June 20, 1940 
COLONIZATION OF JAPANESE BEETLE PARASITES IN 1939 
By J. L. King* senior entomologist, and 
L. B. Parker— ( assistant entomologist, 
Division of Fruit Insect Investations, 
United States Department of Agriculture 
During the active season of 1939 the parasite-colonization work at the 
Japanese beetle laboratory at Moorestown, N.J. , was confined entirely to the 
placement of new colonies of Tiphia species largely within the boundaries of 
generally infested States, 
New importations of Tiphia popilliavora (Korean strain) we re also made for 
rearing purposes, as the older rearing stock had diminished in vitality to such 
an extent that no colonization of this later strain was accomplished in 1939* 
The Spring Tiphia , Tiphia vernalis Roh. 
. Coloni zation in Maryland . — The beetle-infested area in Maryland' was visited 
by representatives of the Bureau of Entomology and Plant Quarantine, in company 
with members of the cooperating group of the University of Maryland in order to 
select new areas for parasite colonization. A number of areas were selected 
and surveyed as to host population and on May 17 the work of colonization was 
started. The liberation of.40 new colonies was made, in 11 counties in Maryland 
in 1939 » which brings the total colonies of T. vernalis to 375 in this State, 
The releasements in 1939* in addition to 3 made in the city of Baltimore, were 
made in the following counties: Cecil, 5; Frederick, 5; Baltimore, 2;' ‘Kent, 5;’ 
Harford, 7* Worcester, 3? Howard, 2; Prince Georges, 3? Anne Arundel, 2; Queen 
Annes, 2; and Talbot, 1. 
Colonization in New York State , —Westchester County, which is heavily 
infested by the Japanese beetle, was surveyed by a representative of the New York 
Agricultural Experiment Station at Geneva, N.Y., working cooperatively with 
Bureau representatives. The habitats selected seem ideal and should yield most 
favorable results in the future. There were 50 releasements made in New York in 
1939* which brings the total releaspments of this species to 62 in that State. 
The 1939 colonies were released in the following counties: Westchester, 44; 
Rockland, 2; Tioga,., 2; Chemung, 1; and Monroe, 1, . ’• 
17 The writers acknowledge the assi stance ' of their associates, J. W. Balock and 
H, J. Willard, who were actively engaged in the many phases of work associated 
with the rearing, collecting, and distribution of parasites. 
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