Middletown transcript., 1900-05-26
The Destructive Pea Louise

The growing Of green peas for the can
merry is one of the most important indus
tries of southern Delaware. One of the
largest pea-canning factories in America,
with a capacity of 125, 900 cans per day is
located at Seaford, and in 1898 this and a
half dozen smaller plants located at Bridge
vile, Harrington, Houston Milford and
Milton packed some 144,00O cases of two
dozen cans each-the crop of over 1000
acres.
During the season of 1899 serious blow
was given this usually profitable industry
by the appearance Of small plant louse
| upon the peas in such countless numbers
as to cause an almost entire loss Of the late
crop and from one-half to two-thirds of
the usual yield Of the earlier sorts. These
small insects, which closely resemble the
"green fly" of greenhouses and the wheat
aphis" on wheat, except that they are con-
siderably larger and entirely Of q light pea
green color, commenced to appear about
the time the early peas were in blossom.
These small insects injure the plant by |
sucking its juices and thus more or less de- |
peting its vitality. Though the few pre-
sent at first did hardly any damage, they |
soon multiplied SO rapidly, that the plants |
were entirely coated withithem. As conse-
quence the vines soon died or very imper-
fectly matured the peas. With the cutting
Of the pea crop these insects were not no.
ticed further excepthere and there in gar
den patches, where they might be found un-
til late in November.
The question most naturally arises at
once, Where were these lice before they
appeared on the peas in the spring or, in
other words, where and in what state do
they pass the winter"
Were it known that the pea louse passed
the winter upon a given weed or crop,
means might be devised for so handling it
as to prevent its spread to the peas. I'm
fortunately last spring the lice were not
noticed until well along in May and in the
fall nothing of definite nature was ascer-
tained as to their winter habits. This year
during the last month, however, the Sta
ton Entomologist has been examining var
ious crops in the vicinity of pea fields to as
certain whether they might not harbor
this pest, and especially those crops which
are in the ground over winter.
Only within the last week has he found
the louise to be excessively numerous on
crimson clover, and though most abundant
in the southern portion of the State, and
near the pea fields so badly in
tested last season, the lice have been found
very numerous as far north as Dover and
not uncommon in New Castle County. |
At BridgeYille the lice are still also almost
entirely confined to the clover, upon which
they occurred in larger numbers than at
any other point which has been visited
and hardly any were found on peas adjoin-
ing the clover. At Harrington the lice
were found rapidly advancing across one
pea field next to clover and quite generally
scattered in another larger plot.
There seems to be but little doubt, there
fore that throughout Delaware most of the
pea lice have spent the winter on the scar. /
let clover and having reproduced so rapidly
as to have become excessively abundant t
lpon it they are spreading ::to the peas.
Only the winged forms will spread to the
peas, upon which they will deposit young,
which will each mature and reproduce 25
o 80 young in from a week to ten days,
md these winged lice are very largely c
pread by the wind.
1t has been ascertained that the Pea r
Iouse, with which as such we were unfa-
niliar previous to 1899, is undoubtedly the
ame as louise noticed for five or six
ears past upon scarlet clover. This was ~
robabfy the same insect which appeared
n such numbers on scarlet clover a few II
ears ago. In one or two instances. 1t
hen threatened the life of the crop, but "
Tas very quickly and almost entirely ex-
srminated by fungous. But few dis "
ased lice have been found this year, and
1ough the clover furnishes peculiarly fav- m
rable conditions for the development of
lis disease, it is doubtful if many lice W
pom the the peas will be killed by it.
II the scarlet clover in the immediate vi
nifty of peas can be turned under deeply
once-commencing upon the side near =.
t the peas-withont doubt most of the br
&c will be destroyed. as they could never
gain the surface, and their otherwise sub pI
quent spread would be prevented. Where
e clover is desired for forage or seed, this vi
ay not seem feasible. It may be worthy
consideration in some cases, however,