10 U.S. NATIONAL MUSEUM BULLETIN 279 



pended on a portable metal stand at a height of 5 feet. One additional 

 sheet was placed flat on the ground on each side of the vertical sheet to 

 silhouette the smaller specimens. The lights were powered by a 12- 

 volt model 50-167 Terado Power inverter connected to a 12-volt car 

 battery. 



A trapline of mammal and bird carcasses was set out in June and 

 July of 1964. The trapline commenced at Nogales, Ariz., and extended 

 eastward through southern Arizona, New Mexico, and central Texas, 

 terminating at the town of Uvalde, Tex. The return tinp to check the 

 trapline was made during the last two weeks of July. Additional car- 

 casses along the trapline and in eastern and southern Texas were 

 investigated. The carcasses proved to be more productive than the 

 black light for the collection of adult Trox and Omorgus. 



The carcass was turned first and all readily visible specimens of 

 Trox retrieved. The debris beneath the carcass and the soil to a depth 

 of about 18 inches were passed through window screening (14- by 

 18-inch mesh). The material that failed to pass was spread out on a 

 piece of canvass sheeting in the sun. The heat from the sun served to 

 "activate" the death feigning, dirt-coated adults so that they could be 

 distinguished from the debris. 



Representative adults and larvae were dropped into KAA solution 

 in the field or placed in individual salve tins for rearing or later fixation. 

 Larvae of Omorgus were placed one to a tin since they are pungacious, 

 whereas several larvae of Trox, especially the smaller species, could be 

 placed in one tin. The adults that were later used for laboratory 

 rearings were placed in Gerber baby food jars (140- ml. size) with 

 perforated screw-cap lids. Each jar was about two-thirds filled with 

 screened sand and a small amount of food. The number of specimens 

 per jar varied from about 10 for those 10 to 12 mm. long to about 50 

 of the 5- to 7-mm. length. The jars were stored in styi'ofoam coolers 

 containing a 2-quart can of ice which was insulated by 1 inch of folded 

 newspaper. This arrangement maintained a temperature of about 60 

 to 70 degrees Fahrenheit within the cooler. About 1,000 live adults 

 were returned to Corvallis by this method. 



Preservation of Specimens 



The larvae were preserved by two methods. In the first method the 

 larvae were placed in a solution of KAA (one part kerosene, one part 

 glacial acetic acid, nine parts 95-percent ethyl alcohol) for 48 hours 

 and then transferred to 95-percent ethyl alcohol for storage. In the 

 second method the larvae were placed in gently boiling water for 

 3 minutes after which the beaker was removed from the heat and the 

 contents allowed to cool. When cool, the larvae were transferred to 



