89 



ments are : (1) That '" the insect is rarely injurious in two consecutive 

 years,"" and {'2) that the remedy consists in a "summer spraying 

 with a dihite kerosene-soap emulsion." ^ These, or similar statements, 

 have appeared in every article heretofore written on this subject, and 

 during the past summer I have been shown a score of letters from 

 entomologists making these statements. 



Early in June of this year I received a note from the chairman of 

 the North Shore Park Commission stating that a committee of the 

 Rogers Park Improvement Association had been aj^pointed to devise 

 means for the elimination of the cottony maple scale. This com- 

 mittee asked me to investigate the subject and undertake the work of 

 spraying in the territory of Rogers Park — a Chicago suburb, but 

 Avithin the city limits. Upon investigation I found the soft or 

 silver-leafed maple (Acer dasycar-putn) to be the principal shade 

 tree here, and every tree was covered with the white egg masses of the 

 Pulvinaria. These insects have been present in this territory in large 

 numbers each year since 1880 at least. In 1807 a large number of 

 the trees were severely pruned, the supposition being that this would 

 eliminate the scale, and the beauty of the trees was thus largely 

 spoiled. The insects have been so numerous that they have destroyed 

 the lower and smaller bi-anches and killed hundreds of trees out- 

 right. The work of the Pulvinaria, together with the pruning in an 

 effort to get rid of it, has caused the trees to look anything but beau- 

 tiful. This same condition exists at other places around Chicago, 

 especially at Evanston and IrA'ing Park. No soft maples are now 

 being planted in this territory on account of the ravages of the insect. 



During the past sununer the eggs were sIoav in hatching, as the 

 season was veiy backward. Up to June 25 practically no eggs were 

 hatched. Two quite Avarm days occurred about July 10, and this 

 served to bring them out. At this tiine the larger limbs and branches 

 were fairly alive with the young going from the egg masses to the 

 leaves. Persons pruning the trees at this time Avould get the insects 

 in the hair and upon the person and clothes in the same manner as 

 chicken mites. The insects were scattered to surrounding shiiibs and 

 flowers in various Avays, especially by the falling of the weakened 

 leaA^es, so that during August they Avere to be found on practically 

 CA^ery shrub. 



The list of plants upon which I haA^e found the Pulvinaria is con- 

 siderably larger than heretofore given. Of course a distinction 

 should be made as to Avhat constitutes the normal food plants, or those 

 upon Avhich it occurs in both summer and Avinter forms and the food 

 plants upon which it may have drifted for the summer. My own 

 observation gives the following as the normal food plants of the 



a Bui. 22, Div. of Ent.. U. S. Dept. Agric, p. 16. 6 Loc. cit. 



