Vol. XL1I April, 1922 No. 4 



BIOLOGICAL BULLETIN 



A WEEK WITH A MINING EUMENID: AN ECOLOGICO 



BEHAVIOR STUDY OF THE NESTING HABITS 



OF ODYNERUS DORSALIS FAB. 



C. H. TURNER, 

 SUMNER TEACHER'S COLLEGE, ST. Louis, Mo. 



HABITAT. 



At the edge of an extensive bottom-land farm near Lebanon, 

 111., there is a large barren tract of land (Fig. I, B). Its northern 

 portion, which resembles roughly the continent of North America, 

 is 80 feet long, 42 feet wide at its greatest breadth, and 9 feet at 

 its narrowest. From the end that is 9 feet wide an arm 300 feet 

 long tapers gradually until it is only 4 feet wide. In August, 1921, 

 to the west and to the south of this desert there was a bottom- 

 land cornfield covering several acres. The ascending slope and 

 the upland on the east were covered with a dense growth of field 

 sorrel, variegated with scattered iron weeds and mallow plants. 

 On the western half of the northern boundary there was a corn- 

 field, and on the eastern portion of that boundary there were plants 

 similar to those on the east. Near the eastern edge of the barren 

 tract the weeds were dwarfs, but they rapidly increased to normal 

 size. From northeast to southwest and then south a small stream 

 meanders through this land. The northern, especially the north- 

 eastern portion, is slightly higher and decidedly drier than the 

 remainder. In meandering through the northeastern portion the 

 streamlet maintains a uniform width of about six inches; in the 

 remainder of the area it frequently widens into shallow lakelets. 

 The flow of the water is continuous, but gentle. This apparently 

 insignificant stream, which is the outlet of a spring with a decidedly 

 salty taste, is the cause of all this barrenness. The minerals it 

 conveys from that spring have destroyed the vegetation. 



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