120 
dead insects which had been collected at Urbana February 23. The 
spechmens were moistened and then rolled about in the fungus spores 
until they were almost completely covered, looking as if they had been 
rolled in flour, ‘They were buried in leaf mould in a crock, which was 
sunk in the earth in the insectary, and aa covered with a board and a 
wet cloth. The first result appeared April 25, when one grub was dead 
and two more were scarcely alive. Others were found dead the 27th 
and 30th, May 2, 7, and 15, and June 1 and 15—twenty-nine in all. An 
external mycelium appeared first April 30, and by May 15 it was pres- 
ent on twenty-two of the grubs, and by June 15 on all but four of the 
lot. Spores were first formed (on two specimens) May 3, and by 
June 1 on several others also. 
A second lot of thirty grubs was dusted with spores of Sporo- 
trichum globuliferum May 9, 1892, from the same culture as that used 
in the above experiment. May 16 nine grubs were dead, and by June 
23 only seven remained alive. Later, three of these died and four be- 
came adults. Dead examples transferred to damp sand May 16, had 
developed spores of Sporotrichum by May 23. From two of them an 
external growth of fertile hyphe took the form of long flattened sheets, 
or bundles, of threads, which spread over the sand three fourths of an 
inch in every direction. Spores were formed in immense numbers on 
the margins and upon the surfaces of this growth. 'These were ripe by 
July 8, and successful cultures of Sporotrichum globuliferwm in its 
usual form were made upon agar by their use. The bodies of those 
erubs that died in the earth after infection, and were left under ground, 
did not grow an external mycelium if the earth was kept wet, but rap- 
idly dec ayed instead, leaving only the thicker chitinous portions of their 
skeleton to indicate their fate. It would seem from this and previous 
experiments that excessive moisture in the earth may possibly prevent 
the post mortem fruiting of Sporotrichum globuliferum by causing a 
too rapid bacterial decomposition of its host. 
Three grubs had died in the check lot during the period of the 
preceding experiment, but none showed any trace of fungus parasitism. 
Two other lots of white grubs, nineteen in each, were treated with 
Sporotrichum spores obtained from cultures August 26, 1892. By Sep- 
tember 24 eleven were dead in one lot and eight in the other. In this 
experiment, as in the preceding one, the dead grubs decayed rapidly when 
left in the earth, and only those lying on the surface, or buried in 
comparatively dry earth near it, ever developed spores. 
So far as we may judge from laboratory experiments only, it would 
seem possible that artificial cultures of Sporotrichum globuliferum may 
be found useful for the destruction of white grubs in the field. Much 
practical experiment will be needed, however, to test this supposition 
thoroughly. 
The most abundant native fungus parasite of the grub, Cordyceps 
melolonthaw, is not, so far as known, capable of artificial cultivation, 
and if used at all, according to our present knowledge of its life his- 
tory it can be conveyed to healthy insects in the field only by infection 
ser in which grubs parasitized by this fungus are used as the start- 
ing point of the infection. I am not aware, however, that any success- 
ful experiments to this effect have yet been made. 
: 
q 
. 
