LOW PRAIRIE 279 
Eubranchipus serratus had disappeared.and Diaptomus was not common. 
Our next record is one month later, when the grasshoppers and other 
prairie or land species had begun to appear. This succession is of 
annual occurrence. The temporary pond community is seasonally 
succeeded by the low prairie community. Flies which breed in water, 
Fic. 280.—A prairie pond, still permanent. 
Fic. 281.—A temporary prairie pond in spring. The short dead grass indicates 
that a crop was harvested the preceding season. 
such as Scoliocentra (Fig. 282) and Tetanocera (Fig. 283), are common 
(also Figs. 284, 285, 286). 5 
2. LOW PRAIRIE ASSOCIATION 
a) The subterranean-ground stratum (Stations 42, 43, 44, 45; Table 
LXV).—Earthworms are abundant. Several of the grasshoppers de- 
posit their eggs in the ground. The larvae of the click-beetle (Melanotus 
