146 
PRIONUS GRUBS. 
(Plate XIII.. Fie:. 3-6.) 
The occasional occurrence in corn of large thick-bodied grubs 
belonging to a different family from the common white grubs 
of this article, calls merely for general mention. The larvae in 
question are those of two species of large brown, flattish, long¬ 
horned beetles ( Cerambycidse ), and belong to the genus Prionus 
imbricornis and P. laticol/is ). They are sometimes common 
in prairie or pasture sod, where they feed upon the roots of 
grass, and have also been a few times reported in corn fields in 
Illinois and Missouri, doing an injury apparently identical with 
that of the white grubs. These larvae are at once distinguisha¬ 
ble from the latter insects by their greater size (3 mm. in length 
and nearly half as thick when full grown), bv the form of the 
body (tapering from the head backwards), and by the fact that 
it is little, if at all, curved. They are, further, at once distin¬ 
guishable by the rudimentary and inconspicuous character of 
their legs. They are much more generally known to economic 
entomology for their injuries to the roots of the vine and apple 
and some forest trees than for their agricultural relations. 
b. Roots penetrated , perforated , irregularly burrowed , and more 
or less eaten off and eaten up. Underground parts of stalk 
usually also similarly injured. 
Wireworms in soil among the roots. 
(I or a discussion of the wireworm injury to corn, see this 
report, p. 28). 
Small , slender , soft-bodied y white or yellowish-white grubs 
in the roots and earth. 
THE SOUTHERN CORN ROOT WORM. 
(Diabrotica 12-punctata , Oliv.) 
(Plate XIV.. Fig. 1-5.) 
Injuries to corn by the southern corn root worm have not 
been seen by us in Northern Illinois and but rarely in the cen- 
tial part of the State, but they are more likely to occur south¬ 
ward. Outside this State they have been recognized bv ento¬ 
mologists in Ohio, Indiana, Kentucky, Arkansas, Mississippi, 
Louisiana, Alabama, South Carolina,, Virginia, and Maryland. 
As the beetle occurs from Canada southward through the Atlan¬ 
tic region, and thence to Minnesota, Kansas, Louisiana, and 
Mexico, it will probably be found much more generally present 
m corn fields than the above report would indicate. 
Its injuries are very similar in general character and effect to 
those ot the much more abundant and better known northern 
oi n loot worm (Diabrotica longicornis ), with which thev have 
