The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1911-12-29

SHIPPERS III THE GREENHOUSE.
BY A. L. Lovett, Assistant Entomolo-
gist at Oregon Agricultural Col
lege, Corvallis.
A florist residing at Albany re-
Gently reported serious injury to his
crysanthemum buds by some insect
closely allied to the chinch bug. A
visit to the ground late this fall
showed the injury to be due to the
Tarnish. Plant Bug (Lygus pratensis
Linn. They are referred to locally
in green house culture as shippers.
This insect occurs In abundance
each year and is common pest all
over the United States. It feeds on
great variety of plants, both wild
and cultivated, apparently the only
requirement is that they be tender
and succulent.
In the Green House.
The shippers attack on plants in
the greenhouse may therefore be
considered due in measure at least
to the maturing or drying up Of it's
host plant outside. They pierce the
stems of the forming buds of the
dahlia, crysanthemum and aster with
their sharp beaks and extract the
plant juices. This puncture apparent
ly sets up a strong irritation, the
stem swells somewhat, becomes
woody and cracks open like a can
ker; the bud withers and either dies
or becomes deformed. They usually
attack the terminal bud first and
where they are numerous may ruin
all the buds as fast as they form.
Its Appearance and Life History.
The adult tarnish plant bug or
skipper is about one-fifth of an inch
long and nearly half as broad. 1t is
elliptical in outline and appears rath-
or f1attened from above. There is a
distinct V just back of the prothorax
and between the wing pads. The gen.
eral color is rather tawny brown
with just hint of green, this varies
from light to dark. From ventral
view the abdomen of the insect is
distinctly green with variable mark
ings of red or brown. The long
piercing beak may be easily seen ly-
ing along the thorax between the
legs.
It is as an adult that this insect
passes the winter alternating under
leaves and trash in sheltered hooks
about the fields and buildings and
in fence corners. In the early spring
they emerge and feed on the stems
and forming buds of whatver host
plant seems most convenient. After
feeding for a time the females de-
posit eggs singly on their host plant
These hatch after a few days into
small very active yellowish green
nymphs that begin at once to pune
ture the plants and suck the sap.
They the gregarious and tend to feed
in colonies at this time and are
often mistaken for green fly by the
florist. After feeding for a time thye
mott and increase in size. They are
still acknowledgment in color, but
now have five distinct black spots
on the back. There are two more
molts before the insect reaches the
adult stage, each time it increases in
size, the color markings more nearly
approach those of the adult and in
the last nymphal stage the wing pads
appear though still very short. In all
stages the, insect is very active, slip
ping around on the opposite side OF
the stem when approached and drop
ping quickly when disturbed. This
new adult begins at once to feed and
deposit eggs in turn. During the
summer season all the variations
from nymph to adult may readily be
found feeding together. The number
of broods per season has not been
carefully determined, but three seems
the number and it is quite probable,
that it is the second and third broOds
that attack greenhouse plants.
Remedial Measures.
Sprays: This insect belongs to
the true bugs which suck their food,
therefore any arsenical is useless in
combating it. Kerosene emulsion is
the standard contact spray and should
be employed where convenient and
practical. In its nymphal stages this
pest is killed with the tobacco sprays
employed for the aphids. Sprays are