Insects Visiting Blossoms of Spirea 121 
existing under conditions which are favorable both to the 
larval and to the adult stages — are strikingly more numer- 
ous than in any other region of the State with which the 
author is acquainted. 
In obtaining the data for this study the insects were col- 
lected from the flowers of approximately the same area at 
intervals of a week. Where the weather made it impossible 
to make the rounds at the stated day, the data was obtained 
the following day or the nearest favorable day succeeding. 
Thus a record was obtained of each seven-day period during 
the season. Most of the collections were made during the 
warmest part of the day between 1:30 and 3:30 p..m., when 
the insects supposedly were feeding in their maximum num- 
bers, and all were made on bright, sunshiny days favorable 
to the insects. It was impracticable to take every insect seen 
on the blossoms on the day of collection, as some of them 
inevitably escaped, but it is believed that approximately the 
same proportion of those active at each period were taken. 
No insects were collected from spireea or blackberry at times 
other than the stated interval except in a few cases where it 
was desired to record certain special data. The collections 
were made at intervals of a week, because there is good 
reason to believe that the life span of at least most of the 
insects which actually feed upon the honey or the pollen of 
flowers (which would include all but the casual visitors to 
spireea blossoms) normally extends over more than that length 
of time. 
Before tabulating and discussing the results of this study it 
might be well to say a few words regarding certain controlling 
natural factors such as climatic conditions. Both the sum- 
mers of 1915 and 1917 were unusual in the lateness of the 
season — the former being remarkable for the cool weather 
as well as for the excessive rainfall during July and August 
in particular. Thus while in 1913 the wild spirea was in 
full bloom and nearly at its maximum during the first week 
in July, and in the following year was at its best during the 
second and third weeks in July, in 1915 and 1917 the first 
blooms did not appear in the region studied until the middle 
