458 
Annual Report of the 
for a remedy, and just as we felt triumphant in our alkaline wash, 
a little chalcis fly made its appearance, the larva of which has taken 
the work out of our hands by effectually destroying almost the en¬ 
tire race of bark lice. This insect has been designated by Dr. Wm. 
LeBarron, state entomologist of Illinois, as the “Chalcideous 'para¬ 
site of the oyster shell-bark-louse 
These parasitic insects are most of them very small, many so small 
as to require the microscope to detect their presence. The late Dr. 
Walsh, says they form about one-fourth of the species of insect life, 
but the number of individuals of the species are comparatively few. 
I have in a measure digressed from my special topic to show the 
unity of all natural science, and that the wider our range of investi¬ 
gation the more will we comprehend and avail ourselves of the 
abundant helps nature has in reserve for our day of greatest need. 
I may also say that the same general principles of destruction apply 
to all the insect foes of our farms and orchards. 
NATURES HELPS. 
The bare mention of these parasitic insects that are known to be the 
farmer’s friends would require more volume than the limits of this 
paper; but I trust our self interest will induce more study of them. 
Great practical good to the agriculturists is to come from a more 
intimate knowledge of this phase of entomolog} r . I will only add, 
that insect life is largely dependent upon the weather; thus a sum¬ 
mer drouth favors the ehich-bug and the aphis or plant-louse, while 
violent and long rains will almost entirely destroy the year’s crop. 
POISONS—CANKER-WORM. 
Next to these, their natural • enemies, we have applications of 
various kinds of poisonous washes. 
The insiduous and slow but sure canker-worm, is as easily de¬ 
stroyed by a wash of paris-green, as is the Colorado beetle, or po¬ 
tato-bug. A strong decoction of tobacco-stems used as a wash in 
winter, will prevent mice and rabbits from gnawing a tree. These 
are also easily destroyed by distributing small bits of apple, carrot, 
and turnip, for the latter, and drops of tallow for the former, in 
which small particles of strychnine have been inserted. 
CODLING MOTH. 
When we have a specific for the codling moth, it will be a happy 
time for the apple-grower. For this little insect, the queen of our 
