137 
to damp sand May 16, had developed spores of Sporotrichum 
by May 23. From two of them an external growth of fertile 
hyphse 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 globuliferum 
in its usual form were made upon agar by their use. The bodies 
of those grubs 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 rapidly decayed 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 fungous 
parasitism. 
Two other lots of white grubs, nineteen in each, were treated 
with Sporotrichum spores obtained from cultures August 26, 
1892. By September 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, Cordy- 
ceps melolonthse , is not, so far as known, capable of artificial 
cultivation, and if used at all, according to our present knowledge 
of its life history it can be conve 3 r ed to healthy insects in the field 
only by infection methods in which grubs parasitized by this 
fungus are used as the starting point of the infection. I am not 
aware, however, that any successful experiments to this effect 
have yet been made. 
DESCRIPTION OF GRUBS. 
Until the publication of the Seventeenth Report from this office 
no distinguishing larval characters had been recognized for the 
larvae of Lachnosterna, and even C 3 r clocephala had not been sepa¬ 
rated in the larval state from the other genera. It has not yet pro¬ 
ven possible to find strict specific characters for the Lachnosterna 
larvae, the distinguishing features recognizable being rather those 
of groups than of species. Three such groups have thus far been 
recognized among larvae subsequently bred, the first represented 
