578 Destruction of Obnoxious Insects by Fungoid Growths. | August, 
Mr. Peck again, in the same report, says, that “ While in the 
Adirondack region, numerous clumps of alders were noticed that 
had their leaves nearly skeletonized by the larve of some un- 
known insect. The larvae were nearly black in color and scarcely 
half an inch long. They were seen in countless numbers feeding 
upon the leaves and threatening by their numbers, even if but 
half of them should come to maturity, in another year to com- 
pletely defoliate the alders of that region. Upon looking under 
the affected bushes for the pupæ of the insect, in order, if possi- 
ble, to have the means of obtaining the species, what was my 
astonishment to find the ground thickly flecked with little white 
floccose masses of mold, and that each one of these tufts of mold 
_ was the downy fungoid shroud of a dead larva from the alders. 
Not a single living pupa could be found, but there were hundreds 
of dead and moldy larvae, killed without doubt by the fungus, 
which is nature’s antidote to an over production of the insect and 
nature’s agency for protecting the alders from utter destruction.” 
The “ pébrine,” a disease which appeared in South France 
nearly thirty years ago and attacked the silk-worms with much 
virulence, is also a case in point. A popular account is given of 
this epizootic in Huxley’s Lay Sermons.’ 
This disease appeared in the rearing houses in great violence in 
1854, although it had been occasionally seen previous to that 
ate. The name “ pébrine” was given to it because of the dark 
spots which appeared on the bodies of the infested larve. 
- The malady spread from year to year, until in 1858 the amount 
of silk produced was diminished to one-third of that which had 
been made previous to 1853. In brief, a microscopic fungus, 
preying upon the silk-worm and causing its destruction by thou- 
sands, prostrated the industries of the city of Lyons, and plunged 
its working class into idleness and want. What the total loss 
was, could not be determined, as all classes of industry suffered, 
but the direct loss was estimated at $250,000,009. ' 
The fact that the insects mentioned by Dr. Hagen exist m 
great numbers, is most favorable to the rapid spread of any dis- 
ease that may appear among them, and the remedy proposed, 
should it work at all, would probably prove powerful, rapid and 
insidious. The spread of the potato rot, Peronospora infestans, 
over the whole of the British Isles within two years after its intro- 
1 Lay Sermons, pp. 373-375- 
