COPEOPHAGOUS BEETLES AND METHODS OF REARING THEM 9 



is plentiful, large quantities of cattle droppings are disturbed by 

 these beetles. No comparative data are at hand on the effect of these 

 insects on horn-fly breeding, but probably fewer horn flies would 

 mature in a dropping that is nearly destroyed. The following obser- 

 vations indicate what sometimes occurs : On April 30, 1932, 12 fresh 

 droppings were examined west of Uvalde, and they were all from 

 one-half to almost totally disintegrated by C. laevis. On May 1, 

 1932, 100 fresh droppings were examined north of Uvalde, and three- 

 fourths were from one-half to almost totally destroyed, in some cases 

 only a cubic inch of dung remaining. In the second instance G. 

 laevis, P. triangularis, and P. colonicus were responsible for the 

 dispersal of dung. The disturbing of droppings by the smaller 

 species of dung beetles in order to hasten desiccation probably 

 causes an unfavorable condition for the horn-fly larvae. There 

 are, however, long periods when the larger species are not active in 

 the field, although activity is fairly constant in the breeding boxes. 



Frequent rains and high humidity increase the activity of these 

 insects, particularly in the spring and summer. It is suspected that 

 in long dry periods large numbers of the beetles are killed as they 

 are ready to emerge from their cells, the balls becoming hard and 

 imprisoning these insects. 



Consideration has been given to the possibilities of artificial en- 

 couragement of certain of these insects with an objective of horn-fly 

 control, but it is believed at present that efforts along other lines, 

 especially with reference to the parasites of horn flies, would be 

 more productive. 



SUMMARY 



In order to study the habits of coprophagous beetles more closely 

 than was possible in the field, several species were reared in the 

 laboratory by placing females in boxes or jars containing sandy 

 soil supplied with fresh dung every few days. 



These beetles, which are called " dung beetles " because they con- 

 struct balls of dung in which to deposit their eggs, show many inter- 

 esting variations in the manner of constructing and placing the 

 balls and in caring for their developing brood. Some species dig 

 a burrow, usually at the edge of cattle droppings, and carry the 

 dung into it for the construction of the ball ; others roll the ball first 

 and then bury it. Most species form balls for adult food as well as 

 egg balls. In some cases several balls are found in one burrow, while 

 in others the egg balls are placed singly. Some species remain in 

 the nest until the developing brood emerge as adults, while others 

 desert their progeny after completing the egg ball. Females that 

 remain in their nests will construct new nests if their progeny are 

 removed. 



Notes on the life histories of four of the most common copropha- 

 gous beetles — Copris remotus, Phanaeus triangularis, Canthon laevis, 

 and Onthophagus anthracinus — are given. 



Dung beetles are also attracted to carcasses and decayed meat. 

 They are frequently found in bait pans of blowfly traps in south- 

 western Texas. 



Because of their disturbance of cattle dung, the breeding medium 

 of the horn fly (Haematobia irritans) , dung beetles are believed to 

 act as a natural control of this pest. 



