292 THE GYPSY MOTH. 



clusters were taken from trees, and, after being prepared in 

 the same manner, were placed in exposed positions on the 

 ground, in the centre of a colony. The tops of the boxes 

 were placed uppermost, so as to give free access to rains, 

 and the localities marked, so that they might be readily found. 

 The boxes were allowed to remain here through all the cold 

 weather and storms of the season, sometimes being bare, and 

 sometimes covered by the ice formed from the melting snow. 



On the 4th of April, all of these egg-clusters, as well as 

 those from underneath the storehouse, were collected and 

 placed in the hatching-boxes. Those from the colony were 

 more or less covered with d&bris which had been carried into 

 the box by the action of rain or of thawing ice. All of the 

 egg-clusters hatched from April 16 to April 20, and, judging 

 from the small number of eggs remaining unhatched, pro- 

 duced as many caterpillars as similar clusters which had been 

 kept intact, either in cold storage or out of doors, during 

 the winter. 



From this it is evident that, although the hairy covering 

 of the egg-cluster may serve in a measure as a protection to 

 the eggs, yet it is not essential to their successful hiber- 

 nation. Certain European writers recommend scraping the 

 eggs from the trees, and state that when this is done their 

 vitality is destroyed by the severity of winter. This cer- 

 tainly is not true in Massachusetts, even if it be so in 

 Europe. 



EFFECT OF EXTEEMES OF TEMPERATURE ON THE EGGS OF 

 THE GYPSY MOTH. 



During the spring of 1895, considerable time was devoted 

 to studying the effect of heat and cold, in extreme degrees, 

 upon the eggs of the gypsy moth, with a view of obtaining 

 a better knowledge of the capabilities of this insect to resist 

 such extremes, which fact has a bearing in showing whether 

 sudden climatic changes would aid in holding the insect in 

 check. 



The experiments with extremes of heat were conducted by 

 use of a hot- water oven, the necessary degree of heat being 

 obtained by means of a small oil stove, and the temperature 

 of the interior being indicated by a small thermometer. 



