
INSECTS INJURIOUS TO THE POTATO. 93 
maturing varieties ; planting these early one year, and digging 
the potatoes in August; then in the following year farmers 
might plant about the first of July, and take them up after 
the frost kills the vines. By this course of treatment these 
potato bugs will be without food during the first fall, and 
many will perish, while those that remain in the ground over 
winter will come up in May, and be without food more than 
a month in the spring, and thus perish. This plan rigidly 
followed will restrain, if not exterminate the bug. 
To this argument some may reply that the potato bug will 
feed on other species of the natural botanical family Solana- 
cee, such as the tomato, thorn-apple,etc. It is true that they ' 
will eat of these to some extent, especially the hungry half- 
grown larve, but I have observed carefully, and never in 
this region saw the young potato bugs developing from the 
eggs laid on these plants, though I have occasionally seen 
eggs on tomato plants. 
Early in the last spring a sufficient number of mature 
potato bugs appeared on the potato vines to cause some 
apprehensions of trouble, though much less than in the pre- 
ceding year. The larve appeared as usual, and early pota- 
toes were partially trimmed by them, from which I inferred 
that the second brood would do a good deal of damage in 
July and August. 
About the middle of July I saw potato bugs in Minne- 
Sota, as far north as St. Paul. They were quite abundant, 
the larvee stripping the vines as they had done in Illinois last 
year. I was at home in Illinois in August, and sought for 
the potato bugs on the same grounds that were entirely over- 
run by them last year, and found very few. At the last of 
August, I searched in the potato patch, on these same 
£rounds, and found but two mature bugs and one small 
_buneh of eggs. Here is a remarkable and unexpected de- 
crease of bugs, instead of the usual increase, that makes them 
. Very destructive in August. How are we to account for it? 
The various known heteropterous enemies, and Lady-birds, 
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