Deseret evening news. [volume] (Great Salt Lake City [Utah]) 1867-1920, 1908-03-03
CERTAIN INSECTS
ARE OUR FRIENDS
How the Dragon Flies and Lace
Wings Fight for the
Farmer.
STORY OF THE APHls LION.
Prof. BAH Gives Valuable Dcmonstra-
ton Before the Normal Students
At the University of Utah.

CReported by j. II. Paul.)
Not all insects are our enemies. ORA
gon flies are beneficial to US through
their entire life histories; the ant-lions
and the caddis flies are beneficial dur
ing much of their history and are never
harmful; but the lace winged fes arc
among the best friends we have These
were the facts brought out in Prof
Balls lectures before the nature study
classes at the state university on Mon
day. He spoke substantially as fol-
lows:
Last time we treated the Orthoptera,
or grasshopper family, nearly all OF
which are injurious. Today we shall
consider the Ueurophra, or dragon fly
order, all of which are beneficial to us
All dragon flies should be spared. The
commonest one, the large dalning nee
die. Is we'll known; but the whole group
is easily distinguished from the pre-
ceding order by the always open and
net-veined wings of the dragon flies,
while all the grasshoppers fold their
wings like fans No other order has
this net-veined structure and biting
mouth parts
THE DRAGON FLY.
The larvae of this beneficial insect
Is even more useful than the adult: for.
While the adult feeds on gnats, mos
quitoes, and flies taken on the wing
the larvae in the water feed upon wig
glers, before the latter pass into mos
quitoes. These larvae furnish good ma
ture study material They live one or.
two years In the water, They can be
fol q =
spring or sumner kept indoors under
water, and fed upon mosquito larvae. or
wiigglers. The eggs OF the dragon fly
are either dropped loosely into the wa
ter or attached to some submerged sub
stance. As soon as they hatch the
young begin an active, predatory war;
fare upon other insects found in the
water including their own kind. The
lower lip of this larva grows to such
size that 1t can be folded to cover tho
lower face like a mask. so that the
front view resembles q bulldogs face.
AS an insect comes near. this mask is
dropped and darted out the insect falls
in, and is seized, and drawn back into
the mouth. When full grown, the
nymph, broad and fiat is unlike either
the slender larva that precedes or the
slender dragon fly into which it
changes. 1t then crawls out of the wa
ter It's skin splits down the back, and
the dragon fly energies. The adults
capture their prey on the wing and
feed on almost all insects. especially the
smaller ones-thc ,-nlts and the midges
Most of ttrse they seize with their feet
and devour them so rapidly that 1t is
almost impossible to see the operation
Files, leaf-honpers. small BUTTERFLIES,
and even small members OF their own
family are eaten by these volacious
creatures, one OF which will eat 40
house flies inside of two hours. As they
are day-niers, the mosquitoes which
fly mostly in the evenings. are not so
numerously Destroyed by the adults as
by the larvae.
THE DAMSEL FLIES,
There are two kinds of dragon flies.
however. A smaller one that folds its
wings when at rest Is called the dam
sci fly. These are graceful species that
fly over large bodies Of sim water, and
are found in great numbers In the reedy
borders of fresh water ponds, flying
low. Another group live in wooded
places along the banks of running
streams. Their wings are frequently
dark, their eyes protruding, their bo-
dies metallic in luster.
,rHE ANT LION.
Among the foothills In sandy places
depressions an inch or so deep, lives
a strange creature called the ant
lion, or doodle bug. 1t has wide
toothed jaws and devours ants and
other insects that slide into its trap,
at the bottom of which only its head
is visible. 1t throws the dry carcas
of the ant out by flip of its head.
II is the larva of an insect that re-
sembles dragon fly. The eggs must
be laid in the sand. AS the larvae
hatch they dig little pits. They
throw out the sand. which they FIRST
heap upon the head, by jerking the
head. The adult flies have short,
dubbed antennae. long abdomens and
recticulated wings, while the dragon
flies have no antcnnae.
THE CADDIEs FLIES.
The caddis files are also called case
bearers. Like the golf caddy, they
carry case, in which they live in
the larval stage for projection. They
may be found in messy places, IN
rocks in rapids, in bayous, and in
shallow water. Each larVa builds for
itself case either OF moss. or stones
or SILICA, or sticks Out of this IL
thrusts It's head and forefeot to walk
and feed, and the case may be seen
climbing a stick whence they have
been called walking sticks, though
trout fishermen know some kinds as
rock rollers. For fish eat them. and
they make good bait They are found
almost everywhere in fresh water.
They can be brought into the school,
room in water and their habits noted.
| They hatch In summer into little
| miller-like flies, which appear IN
! swarms on summer evenings. The
nics lay their eggs on the water.
THE MAY FLIES,
May flies, also called day flies from
the fact that their lives as dying in-
| scots are very short, resemble little
dragon flies. They are like smaller
caddis flies, Gnly that the larvae live
under stones and have no cases. The
adults never feed, and live only a
few days; but the larvae live In water
! about 800 days. Thus they live al
together. two or three times as long
as grasshoppers, In fact. the story
that any insect lives only a day, Is not
| true
THE LACE WINGED FLIES,
These are pretty creatures known
as the golden-eyed lace-winged flies.
|