244 
THE LIVING WORLD. 
The fire-fly and some other species are luminous, but naturalists have not 
yet succeeded in determining the method of the production of light. Beetles 
live separately and in communities; they seem to 
be indifferent to locality ; temperature appears to have 
no effect, and they are practically omnivorous. Their 
irreconcilable enemies are fish, toads, frogs, birds and 
skunks, parasitic flies and worms, wasps, mites and 
parasitic fungi. As a protection, many beetles take 
on the semblance to plants and to different insects. 
The potato beetle deceives the birds by its likeness 
to the potato leaves. Some beetles take on the sem¬ 
blance of fire-flies; some resemble seeds, twigs, and 
parts of plants. So, too, some species feign death as 
a means of escape ; some protect themselves by un¬ 
pleasant odors or by disagreeable secretions. The 
coleoptera minister to the pleasures or necessities of 
mankind, being used for blisters ( cantharides ); for 
medicinal remedies; for viands ; for ornament (chryso- 
chas); and as gladiators. The coleoptera destroy 
myriads of noxious insects, act as scavengers, assist 
in the fertilization of plants, furnish dainty repasts for 
birds and fishes. Their indiscriminate zeal for destruc¬ 
tion makes them unfriendly to crops, lumber, trees, 
books, furniture and carpets. Chief among the scav- 
COLORADO POT v TO-BUG, EGGS AND 
LARVAL NAT. SIZE. 
engers is the 
sea rab ceus , 
though it is 
not known to 
devour putrid 
flesh. It is so 
classed, how¬ 
ever, because 
of its habit of 
depositing its 
eggs in the 
dung of cattle, 
which it gath¬ 
ers, and by 
rolling con¬ 
verts into a 
round ball, 
which is after¬ 
wards buried. 
It is common¬ 
ly known in 
this country 
as the tumble- 
bug , from its 
habit of tumbling about with its ball. 
SACRED SCARABJEUS, OR TUMBLE-BUG. 
In the early age of Egypt it was held sacred. 
