176 MAINE AGRICULTURAL EXPERIMENT STATION. I905. 



19, they were secreting the white sacs and were as far advanced 

 as the slower portion of the cold frame lot, which were ii weeks 

 old. 



As the foregoing observations show, the time required for 

 development depends much upon the temperature, and it seems 

 fair to conclude that a long hot season might give opportunity 

 for 3 broods where the scales are favorably situated. A cold 

 wet summer would probably preclude the development of more 

 than t\vo broods. This seems to be the usual number for Maine, 

 but with such circumstances as scales within a few feet of each 

 other ranging from one day to at least a month in age it would 

 be difficult to be sure that 3 generations were not a frequent 

 occurrence in warm sunny fields. 



A simple test was made with 3 lots of eggs as to their power 

 to withstand cold under unnatural conditions. 



On April 28, two sealed jars containing egg sacs from which 

 the larvse were beginning to emerge were placed in a refrig- 

 erator. These were labeled No. i and No. 2. A third jar, No. 

 3, was filled the same day with egg sacs newly gathered which 

 had not begun to hatch. These jars remained in the refrig- 

 erator until June 6 when they were placed in the greenhouse. 

 June 16 the eggs in jar No. 3 began to hatch. The larvse were 

 liberated among red-top upon which they settled. These 

 developed, secreting egg sacs from the 19th to the last of July. 

 Seven weeks retardation by cold did not injure these eggs. The 

 eggs in jars No. i and No. 2 subjected to the same treatment did 

 not hatch. These, however, were just on the point of hatching 

 when they were placed in the refrigerator and were taken at an 

 unfair advantage. 



KINDS OF GRASSE:S INFEiSTED. 



The egg sacs collected in Alaine have been upon June grass, 

 Poa pratensis, and red-top, Agrostis alba. Where specimens 

 have been sent in on broken bits of grass, as is frequently the 

 case, identification of the host was of course impossible ; but so 

 far as the observations of the past two seasons have gone, these 

 are apparently the only two infested grasses yet reported for 

 Maine. 



