MOIST FOREST MARGIN 263 



2. FIELD AND SHRUB STRATA 



Here two zones may be recognized. While there is no reason for 

 separating them in the ground stratum, a rough separation is here 

 possible. 



a) Rank weeds, willow, dogwood, grape, etc. 



b) Prickly ash thicket with grape and young elms. 



Outside the first is a girdle of low prairie from which low prairie plants 

 and some low prairie animals occasionally invade the forest margin. 



a) Girdle of rank weeds, dogwood, willow, etc. In open, grassy places 

 the garden spiders (Argiope aurantia and trifasciata) (Fig. 255) fasten 



FIG. 254. Low forest margin at Wolf Lake. Ind. In front of a, low prairie 

 area; opposite b, belt of rank weeds: opposite c, low shrubs; opposite d, high shrubs; 

 opposite e, trees. 



their webs to any firm support, such as a young shrub. Various grass- 

 hoppers occur in open situations (Xiphidium fasciatum and brevipenne 

 belong more properly to low prairie) (Fig. 256). The long-bodied spider 

 (Tetragnatha laboriosa) (138) is a common resident. On the grasses 

 beneath the shrubs the black-sided grasshopper (Xiphidium nigropleura) 

 is abundant. The snail (Fig. 257) (Succinea ovalis) is sometimes 

 common. 



Of the bugs which frequent the blossoms of the coarse weeds are the 

 long-legged bug (Neides muticus}, the buffalo tree-hopper (Fig. 259), and 

 the candlehead (Scolops sulcipes) (Fig. 258). These two and especially 

 the latter, with its curiously prolonged prothorax, are the most char- 

 acteristic. The common plant-bug (Lygus pratensis) (Fig. 261) and an 



