INSECT MIGRATION 13 



the cornices of the buildings. It has been noted during every 

 month of the year. 



98. Carpodacus purpureus purpureus. Purple Finch. 



This bird is more or less common during the autumn, winter, 

 and spring, though of rather irregular occurrence. We have records 

 from September 9 (1917) to May 20 (1917). Rather often heard 

 singing in spring. 



99. Astragalinus tristis tristis. American Goldfinch. 

 Occasionally observed, but only in April, May, September, and 



October. 



100. Loxia curvirostra minor. American Crossbill. 

 One noted on January 14, 19 17. 



Insect Migration in Floyd and Adjoining Counties of Iowa. 



BY CARROLL LANE FENTON. 



On September 17, 1915, I noted a flock of Monarch butterflies 

 (Anosia plexippus) resting in an oak grove west of Charles City, 

 Iowa. The flock contained many thousands of individuals, and 

 practically covered the trees for a considerable area. From time 

 to time small numbers of the insects arrived from the north, and 

 occasionally fifty to one hundred would rise into the air and fly 

 to the southeast. In general, though, there was no movement of 

 the flock between the hours of one and five-thirty P. M. In order 

 to form an estimate of the density with which the insects were 

 crowded together I swept my net along a twig, and thirty-seven 

 Monarchs made up the capture. 



Two days afterward I again visited the same locality, and found 

 considerable numbers of Monarchs flying about over a near-by 

 creek or resting on some willows or the lower branches of the oaks. 

 Above the trees were large numbers of these butterflies, steadily 

 flying to the southeast. With the Monarchs were a number of 

 Clover Sulphurs {Colias philodice), these latter being particularly 

 in evidence about the water. While I failed to make detailed 

 observations each day, this migration apparently lasted until 

 about the twenty-third of September. At no other time did I 

 observe such large numbers of butterflies as I had noted on the 



