OAK-ROOT BORERS. 51 
In point of fact, however, in its connection with this tree the beetle shows a sur- 
prising modification of its recorded habits. Its larva is found, not in the stem of the 
mature tree so justly celebrated for its strength and toughness, but always in the 
root of infant trees, and usually in degenerate highland varieties of Quercua virem, 
or of its relatives, Q. aquatica and Q. cateabaei. 
The mother beetle selects small saplings as a place of deposit for her eggs, which 
are laid in the foot, or collar, of the tree, just below the surface of the ground. 
How long a larval existence the insect has is not known, but it must extend over 
several years, since the roots occupied by these larvae grow to a large size, while at 
the same time they show an entirely abnormal development and become a tangle of 
vegetable knots. In fact, the entire root in its growth accommodates itself to the 
requirements of the borer within. Very few new roots are formed, but the old roots 
excavated by the larva are constantly receiving additions of woody layers, which 
are in turn eaten away and huge flattened galleries are formed, which are for the 
most part tightly packed with sawdust. 
The beetle thus becomes, not the destroyer, but the parasite of the tree, and lives 
in a domicile, which may not improperly be termed a gigantic root-gall. The effect 
on the tree is to kill the original sapling, which becomes replaced by a cluster of in- 
significant and straggling suckers, forming perhaps a small clump of underbrush. 
In many cases the branches and leaves are barely sufficient to supply the materials 
for sluggish growth, and the entire strength of the plant goes toward the formation 
of a root plexus, out of all proportion to the growth above ground, and plainly de- 
signed to repair the ravages of the borer. 
The Mallodon borers are very abundant in South Georgia and Florida, and as a 
result of their attacks, vast tracks which might otherwise have become forests, en- 
riching the ground with annual deposits of leaves, are reduced to comparatively bar- 
ren scrub, in which the scattered oak bushes barely suffice to cover the surface of 
the sand. 
Many a new settler, seeing his sandy hill-side covered only by insignificant oak 
bushes, and anticipating easy work in converting the wilderness into a blooming 
garden of orange-trees, has been grievously disappointed to find before him no light 
task in clearing from the soil these gnarled and tangled roots. In fact the great 
strength and weight of the southern grubbing-hoe appears no longer a mystery when 
one contemplates the astonishing pile of "grub roots" which in vigorous hands it 
will extract from a few square rods of apparently unoccupied soil. 
The results of the work of this beetle are very plainly visible around Savannah, 
and especially on Tybee Island, where Mr. George Noble first drew our attention to 
it; while Mr. Hubbard has carefully studied its work, as here recorded, in Florida. 
{Riley's report, 1884.) 
The genus Mallodon contains species of large size with the sides of the prothorax 
armed with numerous small teeth. The head is comparatively large, the eyes 
strongly granulated, distant, transverse, feebly emarginate. The antennas are slender, 
not exceeding half the length of the body in the male and shorter in the female. The 
sexual differences are worthy of note. The prothorax in the male is nearly quadrate, 
densely punctured, with smooth separate facets, while in the female it is narrowed 
in front, more coarsely punctured towards the sides, and uneven on the disk. 
The present species is distinguished by the decidedly serrate prothorax, while the 
tibiae are densely ciliated on the lower edge. It is dark brown, almost black. 
Length, 45 to 55 mm , (1.75 to 2.25 inches). It inhabits Florida, Arkansas and Texas. — 
(Horn.) 
Larva. — Body as large and thick as one's forefinger. It closely resembles the larva 
of Orthosoma brunneum* in general appearance and proportions, but considerably 
thicker. Shape of the prothoracic segment and size of the head and shape of the 
* 1 have no larva of Prionus laticollls with which to compare it, and which it may 
more closely resemble than Orthosoma. 
