The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1909-01-24

with a soft and spongy tissue. These
are not fruits or grOwths natural TO
plants. but abnormal developments due
to fungi or to insects.
New Growth Explained. ~
If we examine the oak appetite rose
gall-we shall find at its center little
cell. In this there is or was tiny lar
va Matched from an egg laid IN the
tissue of the leaf by a small, four
winged insect called a gall fly. AS
soon as the young larva was Matched
and began to eat the leaf, the ieaf-tis-
sue began to grow around the larva and
a large and remarkable bali was formed,
in which the larva both lived and found
food and shelter Each gall fly seems
to select a certain plant for laying its
egg, and each produces a characteristic
kind of gall structure. Calls may be
due to other insects-certain two
winged flies caterpillars, chalcis flies
ana scale insects. A phids also may pro-
duce gals, but these are open at one
end, whence the young issue. Some of
the gall flies transform while within
the Enclosure: others dig their way out
TO pupate in the ground. The oak gals
of commerce come from Europe. Our
own kinds contain much fannie acid
ana DllEIll De uilAlLCQ- dc
Iner says that gallo acid is first formed
at the expense of starch during the
chrysalis stage of the insect, and later
is changed into tannic acid. ''One of
the most peculiar facts connected with
the gall flies is that a particular part
of the plant is always affected by the
same species, and that each species of
the same generation always produces
a reformation or gall of exactly the
same character, so that the gall alone
Identifies the species of insect. How
ard.
When the plant tissue, pierced by the
insect in laying its eggs, closes up by
growth. the insect within must finally
eat it's way cut. Where this has hap
pened, the gals show the exit apertures.
But in the leaf gals of some of the will
lows and aspens. the insect grows till
il simply bursts open the thin leaf COW
ering. On beech leaves a lid-like open
ing of the gall takes place. the insect
then flying away and leaving the chrys-
ais case behind it. In certain solid
gals. when the time approaches for
the iarva to change its quarters and to
enter the pupal stage, a circular piece
like a lid becomes detached from the
lower side, as If it had been cut off by
a knife. The larva tumbles out and
makes its way into the ground. where
il begins to spin. BY the next sprins
ii has entered the pupal stage and the
gall gnat ereeps out of the chrysalis.
Suggestions for Observing.
If you are a teacher. the following
procedure might be especially helpful
in your school room to lend more beau
ty. interest and reality to your daily
classwork. IL you are not a teacher
oil No
good as any others the writer might be
able to give to the beginner who would
like to learn the story of these ODD
xrowths now visible on shrubs and
trees. The student viii soon discover
that they occur IL great variety or
plants of all kinds and on leaves, buds
and flowers, as we'll as upon the stems
of trees.
Bring in knot weeds with white
fungus on the under side of the leaves
examine under a lens to see the blael
spore eases. Find cottonwood leave.
bearing elevations or swellings; whit,
sage stalks with ragged globular tips
sagebrush branches bearing velvetS
globules about the size of small mar
bles; iva with leaves covered by spheri
cal swellings; oak brush, rose busl
branches. willows. etc, bearing hard
swollen knobs. Cut open one or more
of each to discover the small egg
therein. which viii hatch into the lar.
vac of tiny insects. Then recall the
story Of the insects which make theil
homes all winter long in these coz,
dwellings. Here sheltered from the
storms. they get their food. The parent
insect, usually one of the smaller ny
menoptera, has pierced the bud. tn,
flower or the stem with its ovipositor