791 
that it is present in that locality and, since it has "been widely colonized 
in the Lake States, it is possible that it is present at other colony sites. 
In the Eastern States 1_, punctoria is almost as widely dispersed as 
Lydella grisescens and in some localities it is more abundant. In northeastern 
Massachusetts it was the most important parasite and killed 14.9 percent of the 
borers collected. It was reared from 94 percent of the collections obtained 
in this locality. I,, punctoria was reared from 3^ individual collections in 
southeastern Massachusetts and averaged 2.8 percent parasitization of all 
borers observed from this locality. The percentage of parasitization end the 
dispersion of the parasite into new areas showed a gain in 1940 over 1939. In 
1939 the maximum parasitization recorded for this species in any collection 
from this locality was 10.8 percent. In 1940 parasitization by I_. punctoria 
in 7 collections was equal to or above the 1539 maximum. 1. punctoria was re- 
covered from two of the three release points examined in the Connecticut Eiver 
Valley in Massachusetts. At Agawam one collection of borers showed a parasiti- 
zation of 35.8 percent and the average for the area surveyed at this locality 
was 21.4 percent. I_. punctoria was released at Agawam and Hadley in 1936 and 
1 year later at Bernardston, where no recovery was made in 1940. The release 
at the last-named site was made somewhat later in the season and synchroniza- 
tion may not have been accomplished. The area in central Connecticut, center- 
ing at Hartford, in which field-status studies of parp.sites were made in 1939, 
included 133 square miles. This was increased in 1940 to 415 square miles 
but, notwithstanding this large extension, it was found that the parasites had 
dispersed beyond the limits of the survey. I_. punctoria was the most important 
parasite present and parasitized 12.9 percent of the 6,426 hosts observed. It 
was reared from 69, or 80 percent, of the individual collections. Twenty-seven 
collections of host larvae showed 20 percent or higher parasitization by I.. 
punctoria . In the central 95 square miles of the area covered, borer parasit- 
ization by this species at the close of 1939 was 10.2 percent. In the same 
area at the close of 1940 it was 19.9 percent. Parasitization continued to in- 
crease up to the fourteenth host and parasite generation. (The parasite was 
released at Hartford, Conn., in 1934.) Data indicated that 1_, punctoria was 
spreading and increasing most rapidly in .an easterly direction from the point 
of release. It seemed to be retarded in its dispersion toward the southwest, 
possibly because of the prevailing summer winds from that direction. At 
Haddam, M iddlesex County, Conn., I_* punctoria was found to be well established 
following a release of the species at this point in 1935. At Atlantic, Mon- 
mouth County, H. J. , where I_ 0 punctoria was released in 1936, it was found to 
be well ^established, increasing, and spreading. 
Macro cent rus gifuensis Ashm . — A colony of this species was released 
at Adams Township, Lucas County, Ohio, in 1940, to test its reaction in an 
environment where the multiple-generation strain of the borer had become more 
prevalent than it was when the parasite was originally tested in this area. 
Initial establishment was shown by the recovery of two colonies of the species 
in the immediate vicinity of the release point. Initial establishment was also 
noted at two (Bemardston, Eranklin County, and Concord, Middlesex County, MassJ 
of the numerous dispersion colony sites founded in 1940 in the eastern area. 
In southeastern Massachusetts M. gifuensis was the most important parasite. It 
killed 17.1 percent of the 4,345 host larvae observed in the fall of 1940 as 
compared with 10.6 percent of the hosts observed in the fall of 1939. Borers 
