358 
We may add that the larvre of this butterfly, as well as those of the 
other Celtis butterflies (Apatura celtis and A. clyton), are uot voracious 
feeders andean hardly be considered as injurious species except where 
they occur on very young trees planted in the streets. 
ARE TUMBLE-BUGS BENEFICIAL % 
In an interesting article (The Entomologist, vol. xxvn, 1894, pp. 
229-232, and Proc. Ent. Soc, London, 1894, 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 (Diloboderus abderus).* 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 Diloboderus abderus sent to Miss Ormerod 
from such places were two other species of lamellicorn beetles, Eucra- 
nivm arachnoides f and Megathopa violacea, belonging to the so-called 
u 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 efforts in burying dung balls, a sufficient amount of manure 
could be carried underground by them to appreciably 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 fly. 
*The nearest relative to this species in our fauna is Xyloryctes satyrus, whose 
larva is common in the vicinity of Washington among grass roots on pastures and 
deserted fields. This habit 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 short note on the habits of this species in Stett. Ent. Zeit., xxxvu, 
1876, p. 407. ' 
