es 
could be obtained by awaiting the natural Sseasonul sequence. The in- 
sects now available for experimentation include the smaller European 
elm bark beetle (Scolytus multistriatus Marsh.), the elm snout bee- 
tle (Magdalis barbita Say), and the elm borer (Saperda tridentata 
Olav.) 
CEREAL aND FORAGE INSECTS 
P..N. Annand has been appointed as princival entomologist in 
charge of the Division of Cereal and Forage Insects, effective Jan- 
vary 16. At that time W. H. Larrimer was transferred to Arlington 
Farms, Va., where he will be in charge of the cereal and forage in- 
sect work carried on by this Bureau's laboratory located there. 
Influence of planting date on rate of larval survival in 
European corn borer.--Reporting work done by L. H. Patch, B. A. App, 
oe ts DoUtver, Ce A. Crooks, and F. L. Simanton, D. J.°Caffrey, 
Toledo, Ohio, says that the percentage of plants exposing their tas- 
sels near the time when corn borer eggs placed on the plants were 
hatching has been found to be closely associated with the differences 
in the survivai of the borer on different strains of corn planted on 
the same date. To determine whether the same association occurred 
when these strains were planted on different dates, the data from 24 
strains planted on May 19 and June 2, 1933, were rearranged in order 
to facilitate the study. The object of the study was more specifi- 
cally to determine whether an interval of time between the appear- 
ance of the tassels of a group of strains planted on one date, and 
another group of strains planted on a different datc, would be as 
closely associated with the survival of the borer as though the same 
interval had occurred between the appearance of the tassels of two _ 
groups of strains planted on the same date. For this purpose the 
strains of the two plantings were so grouped that the mean tasseling 
date of Group 2 was 4 days later then the mean tasseling date of 
Group 1, both groups being planted on May 19, that the mean tassel- 
ing date of Group 4 was 4 days later than the mean tasseling date of 
Group 3, -both of these. groups being planted on June 2, and that the 
mean taSseling date: cof Group 3 was 4 days later than the tasseling 
date of Group 2, Group 3 being planted on the later date and Group 
2 on the earlier date. Group 2 was composed of the 10 strains of 
the May 19 planting which tasseled latest; Grou»n 1 was the 10 strains 
next preceding Group 2'in tasseling; Group 4 was the 8 strains of the 
June 2 planting which tasseled latest; and Group 3 was composed of 
the 13 strains next preceding Group 4 in tasseling. The mean tassel- 
ing dates, the percentage of the plants showing tassels on July 23, | 
the‘mean percentage of survival of the borer on the groups, and the 
ratios between the borer survival on the groups, in the studies of 
1933, are as follows: . 

