256 PROCEEDINGS OF THE NATIONAL MUSEUM vol. m 



surrounding soil, was slightly darker in color. As it seemed that the 

 burrow might possibly have been filled in, digging was continued. 

 At a depth of 17 inches, slightly to one side, a cell parallel to the 

 surface of the ground was found. It was almost 4 inches long and 

 coa ted on the outside with a few dead leaves, but on the inside it was 

 composed entirely of old cow dung. Near the terminal end of the 

 cell a small second instar was foimd. 



Further digging produced a second cell at a depth of 18 inches, 

 apparently coming from a branch of the burrow which led to the first 

 cell. Two other cells were found, 19 and 24 inches deep, both seem- 

 ingly attached to the same burrow as the others. A fifth cell contain- 

 ing a dead larva was found near the others. As all the cells contained 

 second-stage larvae, further investigation was postponed. A number 

 of the adult beetles, six females and one male, were still alive and they 

 were removed from the cage. 



No further digging was undertaken until Aug. 4, 1952. Then, 

 before attempting to follow any of the burrows, 5 gallons of water 

 was poured into the cage and allowed to settle. This procedure 

 greatly facilitated digging. 



Seven larvae, all small third-stage, were found on this occasion. 

 Four cells were grouped at the end of one burrow; two cells were at the 

 end of another, and one burrow apparently had only a single cell at 

 its end. The depth of the cells ranged from 16 to 20 inches. A 

 diagram of the burrow and cell arrangement is given in plate 10, 

 figure 5. All of the cells were composed of old cow dung, some coated 

 with a thin layer of dead leaves, some without the layer. The larvae 

 overwintered as third iostar, some being kept alive through January 

 1953. 



Pupation probably occiu"s in early summer with adult emergence 

 in July and August. It would seem from the data obtained that the 

 general biology of hornii is quite similar to that of G. stercorarius 

 described by Sano (1915-1916, pp. 25-28). 



The life cycle of Geotruyes hornii apparently takes two years. 

 Freshly emerged adults feed on fungi from July until October, over- 

 wintering in their feeding burrows. Adult activity begins again in 

 April and May. Then, instead of feeding on fungi, the beetles burrow 

 under old dung, with which they provision the larval cells. Oviposi- 

 tion appears to take place in May and June with the larvae becoming 

 third instars by fall. The second winter is passed as a larva, with 

 pupation assumed to occur in early summer. The adults emerge in 

 July and August and begin feeding on fungi. 



Description of Geotrupes hornii larva is based on the following ma- 

 terial reared at Kaleigh, N. C, from adults collected at MUls Kiver, 



