160 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iM 



turned to form the funnel, stapled, and given several coats of brown 

 outdoor paint on both sides. The finished funnel presented a smooth 

 surface and lasted for well over a year. The funnel was held in place 

 by the three wire hooks at the top of the can. The trap was complete 

 when a small vial of attractant was fastened to the inside of the can 

 by a piece of string passed through the holes in the side near the bot- 

 tom. It was then sunk until its top was level with the surface of the 

 ground. Water did not reach the attractant nor accumulate in the 

 can and Geotrupes would survive for a week or more. 



The greatest problem was to find suitable attractants. Warnke 

 (1931) had shown that some chemical products of decomposition were 

 attractive to Geotrupes. The chemicals mentioned by him, plus a 

 number of others recorded as products of the decomposition of plant 

 or animal matter, were tried. There was no attempt made to vary 

 concentrations, as the major purpose was merely to find a material 

 to attract Geotrupes. Three of the materials, isoamjdamine, butyric 

 acid, and propionic acid, proved very successful. The only objec- 

 tion to the use of chemicals was that anything coming in contact 

 with them retained the odor for some time. The chemicals were 

 tried at Ealeigh, N. C, by using them in bait cans placed in a large 

 circle 6 feet apart. Materials that did not prove attractive were dis- 

 continued after several months and others substituted. The data 

 from these traps are summarized in tables 3 and 4 (pp. 241, 267). 

 Some of the better materials were used at Faison and Southern Pines, 

 N. C, with good results. Oddly enough, Geotrupes egeriei would 

 come in numbers to malt, but was not attracted by any of the chemi- 

 cals. A few species, especially in genera other than Geotrupes, were 

 most readily taken in light traps. 



The species collected by these traps and by observation were 

 separated and placed in rearing cages constructed by sinking 12-inch 

 boards 8 inches into the ground, making an enclosure about 2 or 3 

 feet wide by 6 feet long. The soil was disturbed as little as possible 

 in the center of the cages, allowing the adults to burrow to any depth 

 they wished. The beetles were kept supplied with decomposing 

 leaves, cow dung, and fungi or rotting bananas. The enclosures 

 were kept tightly covered with galvanized wire screen. 



In sandy areas, where the species present burrowed to considerable 

 depths, a different type of cage was used that was extremely simple 

 to make. It was merely a tube of galvanized wire screen, 3 feet deep 

 with a varying diameter which averaged about 1 foot. The sides of 

 the tube were fastened together by pulling off a few strands of wire 

 parallel to the cut edges, then pushing the protruding wires through 

 the holes in the screen on the opposite edge and bending them over. 

 A screen top and bottom were fastened on in the same way, making 



