HICKORY ASSOCIATION 



239 



has become loosened, however, we find practically all the small inverte- 

 brates recorded on the ground. The small andrenid bees (Augochlora 

 pura) build small cells under the bank and fill them with pollen. One 

 egg is laid in each cell (July), and the larva feeds upon the pollen. 

 Sowbugs {Cylisticus convexus and Porcellio rathkei) and centipedes 

 (Lithobius, Lysiopetalum lactariutn, and Geophilus rubens) are common. 

 Numerous beetles burrow into the wood or feed on fungi under bark. 

 Some of the chief borers are (Cerambycidae) Prionus and Orthosoma 

 brunneum, and also Passalus comutus. The large slug (Philomycus 

 carolinonsis) is common. 



Fig. 229. — The oak twig primer (Elaphidion villosum Fabr.) (after Washburn) 

 {17th Rept. Minn. Agr. Exp. Sta. y p. 165, Fig. 36). 



b) Field stratum. — After rains the slugs and snails, especially the 

 young, crawl upon the vegetation. Several flies are common (Sapromyza 

 philadelphica). A leaf-hopper (Scaphoideus auronitens), a damsel-bug 

 (Reduviolus annulatus), the shield grasshopper (Atlanticus pachymerus) , 

 and a spider {Theridium frondeum) have all been recorded. 



c) Shrub stratum. — Many spiders build their nests and webs in this 

 stratum. Epeira domicilorum was found with a nest of leaves drawn 

 together adjoining its web. Epeira gigas, the large yellow spider, builds 

 near open places, on high shrubs. The web is a large orb, the nest in a 

 convenient group of leaves near the upper side. 



