358 



We may add that the larvre of this butterfly, as well as those of the 

 other Celtis butterflies {Apaiura celtis aiul A. elyton), are uot voracious 

 feeders and can hardly be considered as itijurious species except where 

 they occur on very young trees planted in the streets. 



ARE TUMBLE-BUGS BENEFICIAL? 



In an interesting article (The Entomologist, vol. xxvii, 1894, pp. 

 229-232, and Proc. Ent. Soc, London, 1891, pp. xx), Miss E. A. Ormerod 

 speaks of the injury done to pasture lands in the Argentine Republic 

 by the larva of a lamellicorn beetle ( DUoboderus abderns)* The inter- 

 esting fact connected therewith is that the injury is followed by an 

 improvement of the pasture, i. e., the coarse and more worthless grasses 

 disappear and the more useful grasses flourish. This improvement 

 has, however, been noticed exclusively on lands that were fenced in 

 and where cattle have been kept. 



Among the specimens of DUoboderus abderus sent to Miss Ormerod 

 from such places were two other species of lamellicorn beetles, Eucva- 

 niiim arachnoides \ and Megathopa violacea, belonging to the so-called 

 "tumble-bugs" which, as is generally known, have the habit of rolling 

 about balls of dung and burying the same in the ground. Various 

 species of these tumble-bugs are known to be extremely abundant in 

 the Argentine Republic, and Miss Ormerod now raises the question 

 whether the improvement of the pastures mentioned above could pos- 

 sibly be attributed to the work of these beetles. This question could 

 only be answered, in our opinion, upon an examination of the pasture 

 lands, but in a general way it may be said that if the tumble-bugs are 

 extremely abundant in a circumscribed locality, where they can concen- 

 trate their eflbrts in burying dung balls, a sufficient amount of manure 

 could be carried underground by them to ai^preciably improve the fertil- 

 ity of the soil. On the other side, where live stock is allowed to roam 

 over large tracts of land the beneficial influence of the beetles is of 

 course so small as to be beyond appreciation. 



Tumble-bugs are extremely abundant in Texas (much more so than 

 in any other portion of the United States), but no one would pretend 

 to assert that the richness of its soil is in any way increased by the 

 action of the beetles. However, when I had lately an opportunity of 

 watching the surprising celerity with which they are able to dispose of 

 patches of cow dung I could not help thinking that they may possibly 

 be beneficial in another way, viz, in preventing the development of 

 many dung-feeding Diptera, and more especially of the horn 1^y. 



*Tlie nearest relative to this species in our fauna is Xijloryctes satyrus, whose 

 larva is common in the vicinity of Washington among grass roots on pastures and 

 deserted fields. Tins hahit has already been observed by Walsh (Amer. Ent., vol. i, 

 p. 60), though later observers found the larva preferably in decaying roots of ash 

 trees. 



tThere is a sliort note on the habits of this species in 8tett. Ent. Zeit., xxxvii, 

 1876, p. 407. 



