THE COTTONY GRASS SCALE. 175 



larvae were emerging were collected in great numbers at 

 Gorham, Portland, Dresden, and along the Eggemoggin Reach. 

 From the middle of October to November 3, 1904, the females 

 were observed to be secreting egg sacs and depositing eggs in 

 fields near Orono, Portland, and Sedgwick, and unhatched egg 

 sacs were gathered in Portland, November 22, 1904. 



Field data, and material sent to this station during 1904 were 

 sufficient proofs of two generations, the first maturing and 

 secreting egg sacs in July and the first of August, and the second 

 depositing eggs (in sacs as before) during late October and 

 early November. In this egg stage the insect winters, the 

 young scales emerging in the spring. 



Life Cycle. — On several occasions, from sacs gathered from 

 different parts of large fields on the same day and kept in jars 

 in the laboratory, all the larvae emerged within a few days of 

 each other. Thus it seemed probable that the life cycle was 

 passed with considerable evenness and regularity. But this 

 conclusion was contradicted by the circumstance that on August 

 1-4, 1904, there were found, within a few feet of each other, sacs 

 in which the eggs were not yet hatched, others from which 

 larvae were emerging and scales of various sizes ranging appar- 

 ently from one to three weeks in age. 



There was no way to tell from field observations as to the 

 exact length of the scale life, so April 12, 1905, egg sacs were 

 gathered for laboratory observations. Many of these were 

 hatched April 28 and the larvae were liberated upon transplanted 

 June grass sod in the greenhouse. They settled upon the grass 

 readily, over 50 placing themselves upon single blades in some 

 cases.- In about two weeks when the scales were well estab- 

 lished the sod was again transplanted to cold frames where the 

 conditions were much as they would be in the open field. They 

 were exposed to much cold weather and considerable rain. On 

 July 12 nine plump sacs newly filled with eggs were picked. It 

 had been 1 1 weeks from the hatching of the scale to the deposi- 

 tion of eggs within the sac. Some of the scales in this lot were 

 not so far advanced and had not begun to deposit eggs, although 

 the scales were covered with a thin cottony secretion. 



An interesting check to these observations was found in a 

 second lot which had developed in the greenhouse upon redtop. 

 The newly hatched larvae were liberated on June 16. On July 



