94 PROCEEDINGS OF THE NATIONAL MUSEUM v'".. ii4 



The female made the cell by packing the dung into the end of the 

 burrow and making a small cavity in the upper end of the dung. 

 A single elongate oval egg 0.8 to 0.9 mm. long and 0.3 to 0.4 mm, 

 wide was fastened by one end to the side of the cavity. Each female 

 produced from 3 to 30 eggs. Two females placed in a flower pot with 

 a single male produced 55 cells. Development was rapid, the eggs 

 hatching in 2 to 4 days, the first two instars lastmg from 7 to 10 days 

 and the third Lnstar 12 to 14 days. (A discussion of the length of 

 development, pictures of the larva and adult, and the effects of gamma 

 radiation on development have been pubhshed elsewhere. See 

 Howden, 1957). Larvae that were observed hatching August 2 

 became pupae on August 31. Before pupation, the larva forms a 

 hard spherical pupal cell of its own feces inside the dung wad. The 

 pupal period lasts only 5 to 7 days but the teneral adult may remain 

 in the pupal cell for several weeks. Once the adult emerges, mating, 

 though not observed, apparently is not long delayed, for females 

 start cell formation shortly after their appearance. It is interesting 

 to note that isolated virgin females do little burrowing in comparison 

 with mated females. Active beetles lived for 2 to 3 weeks under 

 laboratory conditions. At least six generations were reared, starting 

 with the two females fertilized by a single male. 



At almost any point in the above cycle, adverse conditions may 

 change the length of time required for development. Either too 

 moist or too dry conditions in the flower pots caused considerable 

 mortality. Moistm-e favored the appearance of fungi in the cells. 

 However, mites were the most difficult problem to contend with in the 

 flower pots; frequent changes were necessary, because if the adults 

 were left in pots where the mite population was large, the mites would 

 actuaUy kill the beetles. Occasional specimens in the field have 

 been noted infested with mites, but how serious a pest they are to 

 the coprophagous beetles remains an interesting problem. 



Kemarks. — Boucomont (1932) placed 0. texanus as a variety 

 of 0. landolti, and unquestionably it is very close. We prefer at 

 present to give texanus subspecies status. It differs from typical 

 landolti in that it is less shining and more noticeably alutaceous. 

 The pronotum is usuaUy black or brown, only rarely with a greenish 

 cast, whereas in landolti it is frequently bright green or coppery. 

 The pygidium is always bicolored, often being yellow over more 

 than half its surface, but in landolti the pygidium is black or only 

 the edges are narrowly yellow. The apical black spot of the elytral 

 declivity is more romided higher up, and is opposite the 4th and 5th 

 intervals; in landolti the spot is elongate, nearer the edge, and opposite 

 intervals 3, 4, and 5; the males of texanus never have the anterior 

 arcuate pronotal carina which is sometimes evident in landolti. 



