BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 
53 
for 3 years as possibly showing inherent resistance, the Bantam selec- 
tions made the most favorable showing. Further breeding experi- 
ments are necessary before tentative conclusions can be drawn. Accept - 
able evidence of inherent resistance was available, however., for Bantam 
strain Michigan 1828, Iowa 9, Iowa 45. Minnesota 26-34. Minn. 1:3-34. 
Purdue 14. and Michigan 1923. Several strains of Evergreen also 
gave satisfactory evidence of such resistance. 
In general the tests for 1939 of resistance in field corn substantiated 
the results of previous years. Such lines as R4. L317B2. Mich. 77. and 
Mich. 106 continued to exhibit material resistance. A strain, 1205, 
formerly considered resistant, failed in 1939 to maintain this quality. 
Six additional inbreds. viz, Kan. G30. Kan. G26. Ia. R. D. 817, Mich. 
285, Ohio 3113-X-1-1-1-2-1. and Ia. Ldg., exhibited resistance, both 
in 1938 and in 1939. 
In some successful spray formulas for corn borer control in early- 
market sweet corn, an important ingredient was Chinese gallotannin, 
but owing to its high price and the increasing difficulty of obtaining it. 
efforts were made in 1939 to find a suitable substitute. This apparently 
has been discovered in myrobalans tannin extracted from the dried 
fruit of plants of the genus Tt rminalia originating in India. Its per- 
formance indicates that with certain adjustments it promises improve- 
ment on Chinese gallotannin. Quabracho extract, another tannin, 
showed high effectiveness, although its extreme solubility render- it 
of doubtful utility during wet weather. Cryolite was again found 
effective as a borer insecticide on sweet corn, but attempts to eliminate 
its burning effect on the plants were not successful. 
During 1939 a total of 81,452 adult parasites of the European corn 
borer were utilized in the colonization program. In handling these 
the shipping mortality was less than 1 percent of the whole number. 
In this work the four species Ghelonus asrimtlipes Wesm., Mocrocenf rus 
gifuensis Ashm., Lydella grisescens R. D., and Phaeogenes rdgridt ns 
Wesm. were released. 
Emphasis was placed especially on the distribution of the egg-larval 
parasite Ghelonus amvulipes in the Connecticut River Valley and the 
lower Hudson River Valley. A total of 47,724 adults of that species 
were liberated in Connecticut, 22.826 in Xew York State, and 4,476 in 
Indiana. Colonies of the polyembryonic Macrooi ntrm gifm nsis were 
liberated in the heavily infested areas of Ulster County, X. Y.. and 
Atlantic and Burlington Counties. X. J. 
INSECTS ATTACKING SMALL GRAINS 
In a continuation of the work of breeding wheats resistant to attack 
by the hessian fly, a 3-acre field test in California of a resistant hybrid 
carrying the fly-resistant characteristics of Dawson wheat and desig- 
nated as "Big Club 38" showed complete freedom from fly infestation 
as compared with 70-percent infestation in the check plots of ordinary 
Big Club wheat. In the breeding of fly- and disease-resistant Soft Red 
Winter wheats, progress was excellent and the results corroborated 
those obtained in 1938. which indicated that a number of hybrids based 
on two highly fly-resistant varieties of spring wheat possessed distinct 
resistance to the fly. In similar work with the Hard Red Winter 
wheats in Kansas as many as 50 percent of the lightly infested F 4 selec- 
tions showed entire absence of infestation in the fall. The infesta- 
