Saint Mary's beacon. [volume] (Leonard Town, Md.) 1867-1983, 1875-06-17
(From the N. Y. Herald.)
- THE POTATO BUG.

now almost universally called Dorg-
Phoru deeesn .iineafa, or the ''ten-lined
spearman'), belongs to the family of
leaf-eating beetles (Chrysomelidr), and
IL one of the largest of the group. The
perfect insect measures about half an
inch in length, is Of thick oval shape
and Of a yellowish cream color, with ten
dark brown or blackish lines running
lengthwise down the wing covers. The
bead and thorax, or middle portion Of the
BODY, are Of an orange-brown color,
spotted or marked with black. It has,
in addition TO the wing covers, a pair of
pink wings, which lie folded beneath and
hidden except when the insect is in fight.
The eggs, to the number of 1000 to
1,2OO and even more, are deposited upon
the young leaves of the potato in clus-
ters, containing from one TO two doze,
each. These hatch in very few days,
and the young Larvae go Immediately to
work on the foliage and acquire their
full size in less than three weeks. In
color they are dark orange-red, the
head black and black ring on the first
segment Of the body, and q double row
= of black dots down each side, from the
head to the end of the abdomen. Af-
ter arriving at maturity the arvn go
into the ground and change to purple,
and in about ten days or two weeks the
perfect beetles appear. They begin to
pair in about a week, and on the four
teenth day the female begins to depo-
sit her eggs, SO We may consider that
it takes about fifty days for the insect
to go through all its changes from egg
to egg. though, of course, the time may
vary little from differences in temper
ature, &c. A writer in the Canadian
Entomclogist estimated that if the prog
eny of q single pair of these insects were
allowed to increase without molestaticn
for an entire season the results would
amount to over 6O,OO0,OOO of indivi1.
uals, which will give some idea Of tineir
powers of reproduction. Thou h the
potato is its particular food it vii, feed
upon other plants, such as the tomato,
egg plant, &c, sometimes doing con-
siderable damage, and in one case repor.
ted, after destroying c field of potatoes,
they finished ~ on a patch of the
jamestown weed (DGtura Strdmoaiam. }
There is another insect closely allied
TO the Colorado beetle called the false
potato beetle (Doryph0rd jnnctr) J, which
Is Sometimes mistaken for the genuine
species especially in uninvaded dis
tricts, often causing needless alal m.
1t differs from the true species in hav-
ing hut eight stripes, tn. ones on eth
er side of tie wing covers being as
broad again, as If two stripes had been
united or run together. The larva also
differs, in being much lighter colored
(more of = flesh color, in facD and in
having but one row of dots down the
sides Of the body. This species has ex-
listed inthe East for many years and lives
upon the horse nettle, egg plant, &c. The
old-fashioncd nder-s,ripcd potato
bugs" (cdntharis or lyttn) have also been
confounded with the Western species,
but their long, soft bodies easily dis
tinguish them.
1t is difficult to estimate the amount
of actual damage done hy these insects
over the whole country for Il given year
AS the beetles invade new territory
where the farmers are wholly unrrtpar-
cd for them, and. indeed, know little or
nothing of the foe with which they have
to contend or the best mode Of warfare
against them, they are very naturally
more destructive than year or two
later, when their habits are better un-
dcrstood aud the best means of pre-
vention have become known. That
they are more or less destructive GER
tain Years is doubtless rs true with this
insect Us with many other dcstructiy,
species. In 1872 the general opinion
prevailed that they were not So plcnt,
as in previous years, but certainly they
have been at work i'll good earnest dur.
ing the last season. and from the ear.
" reports received this year il is pre-.
bable that they will be fully us dcstruc.
tive the present season. The question
is often asked, "Will they always re.
maiu z" To which We can only answer
Yes, though probably during the first
two or three years of their appearance,
in new locality they will be the most
destructive.
The value of potatoes in local mar.
kets has averaged fully SSo, ,0O0. 900 70,
The whole crop since the prevalence OF
the potato beetle. The yield has been
about l20, 900, 900 bushels per annum
and the loss from these insects NAV b.
considered an under estimate at Sl2.
100000 per year. As the price has ad
tanced with the decline cf production
The consumer has shared with the pro.
ducer the los, yet an intrinsic value ot
$S,Oo0,O0o per annum has been sacri
feed. with large additional amount
for the application of Paris green. tn,
labor of hand picking and other expe.
dients employed in the desperate con.
test between Dorypkora and the potato
grower. To illustrate-Illinois with.
stood the Srst serious shock in this com.
bat in 1867, and the total production
fell of 80 per cent. the rate of vield
declined from So to 90 bushels ger acr,
(aecording TO records of the Depart.
ment Of Agricultrre). and the averax,
price almost doubled. In 1868 the viclt
was increased 20 Il bushels, and il
1869 there was further Improvement
and an increase IN quantity of 5000,
600 or 4.0O0, 900 bushels. Striking ou
Indiana the rate of yield fell of NOR,
than half, and the price doubled. Ii
1870 the beetle began to invade Ohio i,
earnest, and the State returns show
decsiae from 9,627 ,75s bushels in lse