I N SECT PEST SURVEY BULL E TIN 
Vol. 17 Supplement to No. 8 October 25-, 1937 
LIBERATIONS OF PARASITES OF THE EUROPEAN CORN BORER 
IN TEE UNITED STATES IN 1337 
By Charles A. Clerk ,.i/a ssocia te ento mo logi st 
Pivision of Cere al" and Forage Insect Investi g ations 
United S t - teg Departmen t of Agri culture 
The 1937 program for colonization of parasites of the European corn 
borer was conducted essentially as were those of the preceding 3 years. Adult 
parasi.tes were reared from, domestically collected host larvae or from similar 
material imported from Europe. All adult parasites emerged at the Moorestown, 
N. J. , laboratory and were taken from there directly to the field or were 
shipped in iced containers by rail to other laboratories for release in ad- 
jacent infested regions., A total of 2I,47C adults were released during'the 
season, which (see Insect Pest Survey Bull. v. 16, no. 9, Sup., Dec. 20, 1936) 
brings the grand total of corn borer parasites released in the_ United States to 
date to over 5,660,000. A summary of the 1937 releases of the various parasites 
is given, by States, counties, and townships in table 1. 
Ina rcolata punctoria Roman. — Emphasis was ^ again placed on the further 
distribution of the ichneumpnid I. punctor ia over the' previously uncolonized 
infested area. A 1937 release of this species was made in Northampton County, 
Vc . , where it had boen previously released in' 1956, as the borer was reported 
to be rapidly increasing in that locality and it w s thought that the parasite 
did not h ve a satisfactory nhv.nce of establishment in 1236, bocause of the un- 
usual and severe drought of that year. In '11, 16 releases of this larval 
paras it-., wore made in as many counties located in 7 St- t ... . The number of 
adults released in 1937 was 8,827, bringing the total number to 138,577 released 
since the beginning of th-j corn borer parasite work. At the close of the 1937 
season this parasite h' d been released in practic-. lly all counties known to have 
sufficient corn borer infestation to justify such releases. Liber? tions of this 
species wore made in the eastern area rrom Chittenden County, in northern Ver- 
mont, to and including Northampton County, on the Eastern Shore of Virginia. 
-'D. W. Jones, W. G. Bradley, E. W. Beck, E. D. Burgess, and K. D. Arbuthnot 
assisted with the releases of the parasites over the infested area. 
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