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parasitization has always been much higher, usually at least twice as high, 
on the first or summer generation than on the overwintering generation. 
In 1 Q 77 this was not the case, the parasitization of the 
horers as determined in the fall survey, being higher than in the Previous 
sZe^ Indicating that the parasites have already started a return toward 
the normal equilibrium position, believed to be approximately 15 percen 
for the parasite complex on the overwintering borers in this region. 
It should he emphasized that the above discussion concerns only the 
central 154 square miles of the Malden district comparable to the area 
surveyed in previous years. The dispersal of the parasites has continue 
with the result that the region surveyed in 193 ° was increased to cover 
a circular area 26 miles in diameter, or 531 square miles, and increased 
again in 1937 to cover a region 36 miles in diameter, or a territory of 
1,018 square miles. The total parasitization in the 531 square miles sur- 
veyed in 1936 was found to be 14.90 percent, but in the fall of 1937 ^ 0 
parasitization in this same territory wa^ only 7*95 percent, showing that 
the same decrease that had taken place in the central district had also 
occurred in this larger district. The parasitization of the corn borer 
in the whole Malden area of 1,018 square miles at the close of 1937 was 
found to average 5*44 percent. 
The Taunton, Mass., area .— Prior to 1937 a number of small surveys for 
parasites had been conducted in southeastern Massachusetts and eastern 
Rhode Island. In 1934 Lydella griscscens was the only parasite recovered 
from survey collections made at East Providence, R. I., and Bridgewater, 
Mass.; however, ono mass of cocoons of Macrocentrus gifuensis was found 
in that year in the course of other work near Bridgewater. 
In the fall of 1935 a district 5 miles in diameter, or approximately 
19^ square miles in area, was surveyed at East Providence. Lydella grises- 
cens was again recovered, as in 1934, but Inareolata punctoria was also 
found to be present in measurable numbers. At the Bridgewater point, 
collections over a district 3 miles in diameter, or about 7h square miles, 
failed to show the presence of M. gifuensis or I_. punctoria , but L. grisoa- 
cens was again recovered. As numerous releases of several species of para- 
sites had been made over a period of years up to 1932 in a district 
extending from Taunton to Swansea, Mass., a survey of a strip 2 miles wide 
and l4 miles long was made in this district in 1935* In addition to reveal- 
ing the presence of L. grisescens and _I. punctoria , the survey also showed 
that Ohelonus annul ipes was present in considerable numbers at Pighton and 
Taunton. 
In 1936 a survey, of 78.5 square miles around Pighton showed that 
Chelonus annul ipes was present over this territory and, from its recovery 
at the outer edge of this district, probably beyond the limits of the sur- 
vey. Lydella grisescens and Inareolat a punctoria were also found through- 
out this district, and Macrocentrus g ifuensis was recovered in numbers 
from some sections. A survey at Bridgewater of a larger area than in 1935 
( 19u square miles in 1936 as compared to square miles in 1935) confirmed 
the presence of M. gifuensis , first found in 1934. 
