STATE AGRICULTURAL SOCIETY. 
THREE-LINED POTATO-BEETLE. ALARM FROM IT. 
441 
15, Three-lined Potato-beetle, Criocerix (Lema) trilineata, Olivier. (Cole- 
optera. Crioceridm.) 
Eating the leaves of the potato in July and August; small yellowish worms with black heads 
and feet, in clusters on the underside of the leaves, wet and ooated over with slimy filth; 
passing their pupa state under ground and producing oblong bright tawny yellow beetles a 
quarter of an inch long and having three black stripes on their wing-oovers. 
In the central parts of our State this past year (1864,) in the fore part 
of July, public attention became directed to a worm which was discovered 
eating the leaves of the potato vines. It was found to be quite common 
all over the potato fields, and excited considerable alarm. Having never 
been noticed before, it was thought to be a new enemy, which it was 
greatly feared would multiply and seriously damage this important crop. 
Accounts of it were published in some of the local newspapers, and a cor¬ 
respondent of the Rural New Yorker having transmitted specimens of it 
to that periodical, they were forwarded to me for information, coming to 
hand July 17th. These specimens being of a soft worm, and pressed in a 
paper envelope, wevo too distorted, dried and faded, to show definitely 
what particular species they were. An inspection of them, fyowever, in 
connection with the information gathered from an article in the Fulton 
(Oswego' Co.) Patriot under date of July 13th—to the effect that these 
potato worms resided on the underside of the leaves, and were “from a 
fourth to a third of an inch long and an eighth of an inch thick, red orange 
with a black head and six black legs on the forward half of the body”— 
led me to infer with considerable confidence that they were the larva: of 
the Three-lined Potato-beetle, which occurs, more or less common every 
year, in the potato fields all over our country; though they might perhaps 
be the similarly shaped and colored larvae of the fearfully destructive Ten- 
lined Potato-beetle of the West, newly introduced into our State in some 
unknown manner. An article embodying these facts and giving such a 
description of these two insects as would enable any one having either of 
them before him, to determine which species it was, was thereupon pub. 
lished in the' Rural New Yorker. The public anxiety appeared to be imme¬ 
diately abated thereby, as I have heard nothing further of these worms. 
Of the injurious insects which are constantly present in our potato fields, 
this Three-lined Potato-beetle is the most important. Living as it does, at 
the expense of one of our most valuable field crops, its history and habits 
merit to be generally known, although fortunately for us it never becomes 
so greatly multiplied as to occasion any serious injury. 
These beetles begin to be seen abroad each year about the middle of 
May. Dr. Harris states (Treatise, 2d ed., p. 105) that the larvae in autumn 
go into the ground and there remain during the winter in their pupa state, 
to give out the perfect insects the following spring. But, as I have found 
these beetles torpid under boards lying on the surface of the ground, as 
early as the 201 li of April, 1 infer that it is in their perfect state that they 
pass the winter, like the Asparagus-beetle and other kindred species. The 
first individuals which 1 have met with abroad, in different years, have 
been upon the leaves of bushes and trees in the woods, from which it 
