October, '12] HOUSER: SCIARA LARVAL CHAINS 399 



SCIARA SCIOPHILA LARVAE CONGREGATING IN CHAINS 



By J. S. HousER, Department of Entomology, Ohio Agricultural Experiment 

 Station, Wooster, Ohio 



About the middle of July of the present year there was reported 

 to this department by Mr. C. R. Neillie, of the Cleveland City Depart- 

 ment of Forestry, a serious outbreak of this insect, occurring on a 

 lawn in Shaker Heights, Cleveland, Ohio. The writer was detailed 

 to investigate the trouble and found that the insects had been present 

 for two or three weeks. During this interval, on account of their 

 repulsive appearance; they had been causing, the inhabitants of the 

 place a great deal of discomfort. 



I was told by one member of the household as well as by the gardener, 

 that the larvae, especially in the early mornings, had exhibited a 

 tendency common with some members of this family, to march in 

 chains about the lawn, on the drives, along the foundation of the 

 house and in similar places, but I was unfortunate in arriving just 

 after the gardener had completed his customary morning rounds of 

 pouring gasoline upon the insects and hence I did not see them in 

 motion. The columns, however, were said to have varied in size from 

 a half inch in width and two or three inches long, to those four inches 

 in width and two or three feet long. 



Something of the magnitude of the scourge may be gained from the 

 fact that about a hundred gallons of gasoline had been used for killing 

 the insects and that the putrid decaying masses of their bodies were 

 to be seen in sheltered crannies everywhere, though in greater quan- 

 tity along the walls of the house, at the bases of trees, along the sides 

 of the walks, etc. On a number of places in the lawn, grass had been 

 killed by the gasoline over areas of several square feet. 



At the time of my visit the numbers of the larvae were decreasing, 

 but the flies were still abundant on the lawn and in the bordering woods. 

 A collection was taken from both places, as was also one of larvae 

 and pupae from the decaying mould of the woods. Within a short 

 time adults emerged from the latter, and specimens of all three lots 

 were sent to Dr. O. A. Johannsen, to whom I am indebted for the 

 determination of the species. The insects developed not only in the 

 woods, but in the lawn proper as well, for both larvae and pupae were 

 found in the turf. As far as I was able to determine, the scourge 

 was confined to the one lawn of about an acre and a half in extent. 



