150 
species July 5, and Webster reports it as pairing in Central In" 
diana in July. Dr. Riley seems to have found eggs of beetles 
in his bleeding cages July (, from individuals which emerged 
the day preceding, the larvae having originally come from Vir¬ 
ginia June 18. (Jarman finds the ovarian eggs of this (?) Gen¬ 
era tion mature in Kentucky July 29, these two being as °yet 
the only observations on record concerning the egg. 
The pupation of this brood of larvae is not, however, alto¬ 
gether completed in Illinois before the end of July. Indeed, larvae 
taken (Le ^Oth of August at Champaign, Illinois, in 1889, were 
possibly of this same brood. The beetles have begun to pair 
again, however, as early as August 8 with us, and young root 
worms, doubtless of a second generation, have been collected at 
Champaign September 6. Garman's observations in Kentucky 
are not especially different from these, but the dates given for 
Alabama (“Insect Life,’" A ol. IV., p. 104) show a much earlier 
start of the species. The active larva is reported as occurring 
there from March to the middle of May, these earlier larvte be¬ 
ginning to pupate certainly by April 30, and to yield the imago 
Ma} 21. The occurrence in Minnesota of pupae September 3, 
which gave the imago three days afterwards, is a fact which 
has no special bearing upon this life history. 
I need only add that the eggs are placed, either singly or in 
groups of two to twelve or more, according to Rilev’s observa¬ 
tions, below the surface of the soil near the plants, in cracks 
or immediately a,bout the base of the plants. 
NATURAL ENEMIES. 
So far as now known, the most effective natural check on the 
multiplication of this insect is a bacterial parasite (Bacillus rufans) 
observed by me to infest the larva, killing about three fourths 
of a considerable collection of these corn root worms brought 
from Jacksonville July 19, 1889. We do not yet know what 
part of the larva is first attacked by this Bacillus , but by the 
time the resulting disease has reached a fatal stage, it swarms 
in all the fluids of the root worm, which have become practically 
a pure culture of this bacterial species. Infested larvae lose their 
characteristic yellowish tinge, becoming gray and somewhat 
swollen, and after death they change color through pinkish to 
dull dark red, the internal organs breaking up to a fluid pulp, 
held for a considerable time in the tough cuticle of the dead 
larva. The fluids of such specimens have a milky appearance 
in the pale worms and a reddish tint in the others. ‘This last 
color is due, not to the color of the bacilli themselves but to 
an excreted coloring matter diffused through the fluids in which 
they grow. In artificial cultures, consequently,—a number of 
which I made in 1889,—a similar color is imparted to the cul¬ 
ture medium, whether this be solid or fluid. 
