Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-01-07

bringing up are such az
are OF economic importance: that is to say,
which are injurious or beneficial TO useful
plants. Like other animals they require plenty
of light and the air is kept warm and moist all
through the winter for the benefit of their
health
Along shelves in the conservatory are ranged
a great number of glass receptacles Of different
sizes. Some Of them are ordinary jelly glasses,
while others are large jars, and yet others are
tubes open at one end only and corked tightly
with plugs of cotton. Each of these contains
insects of some kind in process of development,
though just now most of them are torpid. pass
ing the winter in the chrysalis. For example,
in one jar are two or three sunaower heads
which were infested by the larya of beetle.
The little worms have buried themselves in the
sand with which the vessel is half filed and next
spring they will emerge as perfect beetles, ready
to lay their eggs in fresh surflowers.
BY thus combining an insect where it can be
watched its life history may he studied at
leisure. All its transformations may be noted,
the breeding being carried on with many
species for generation after generation. In q
small jar half full of beans there hundreds
of bean-esting bugs. which will continue to re-
produce their kind so long as the food supply
holds out. similar receptacle contains sew
era. immature grasehoppers buried in earth,
which have been there six years. They will
not come out rs perfect locusts for
eleven years more, because they are
of the seventeen-year variety. By this
sort of biological observation il is discovered
how and at what stage of its existence each
injurious insect can be attacked most adj
vantageously. Most of the jars are covered
with muslin game, so as to admit the air. while
others are closed with glass tops to retain
moisture.
SOME CURIOUS SPECIMENS.
In one jelly glass filed with little flies is an
Irish potato riddled with holes by the maggot-
like Larvae of the flies. A jar contains a few
twigs infested with little worms. which will
come ont after while as beetles. In another
receptacle half full of sand come yucca
pods living about They have been abandoned
by certain grubs. which have buried themselves
in the sand, where they will undergo a trans
formation. emerging next spring at the blossom
ing time of the yucca in the shape Of white
moths. Yet another vessel holds half q dozen
huge oak gals, three inches in diameter. They
are tumor-hhe excrescences caused by small
gnat-like insects which sting the stem OF the
plant in hundreds of places close together,
depositing an egg in each wound. Thus irri-
tated the tree forms over the injured part an
odd-looking growth, which serves to protect
the offspring Of the gall bug until they are
ready to go out into the world and Law more
Some gals woolly and others are of bril-
liant colors. They have many commercial and
medicinal uses.
Every day all the glass receptacles are exam
ined. Newly Matched insects, when wanted.
are removed and killed, after which they are
stuck on pins in boxes, arranged according to
species books are arranged in library.
The boxes, shaped like hollow books and open
ing in the same way, are similarly placed in
rows on shelves, the back Of each one labeled
A catalogue serves as an index to the entire
collection, every individual bug having a num-
Der. Up to date only a small fraction of the
insects in the world have been named and clas-
sifed. it being estimated that not less than
10. 0o0, 900 species exist.
In one jar are few pieces of bark honey
combed by woodborers. In this case sawdust
instead Of sand is provided for the Larvae to
as flies. A jelly glass contains q little wheat
flour, together with some beetles Of kind that
devours stored grain and -four. These latter
are readily bred and can be watched throughout
their development from the egg to the larval
form and from the latter to the beetle. In like
with kernels Of wheat, and '.joint worms" are
observed in the act of feeding upon stems of
the wheat plant Root-attacking bugs are
propagated very simply in earth in potts. to-
gether with the growing plants whose roots
they feed upon. To prevent them from escap-
ing wQen tQev come out OF the ground glass
jars are inverted over plants ana pots.
An important feature of this work is the
study of parasites of the insects themselves.
There is hardly any kind of bug which is not
proved upon by one or more other species. As
DIR. johnson remarks:
"Great leas have little fleas upon their backs
to bite EN-;
While they in turn have lesser ones, and SO ad
infinitum."
SAVING OF CROPS BY THE KNOWLEDGE GAINED.
So it is with other insects, and the best way
to exterminate pestiferous bug is often to
introduce hostile species to the region where
the damage is being done. In this manner the
Department of Agriculture has saved the
industry of California from
being destroyed by the fluted scale insect by
importing from Australia the lady-bird bug.
which preys upon the scale. The operations of
such parasites are watched in the same jars with
the insects fed upon, and thus knowledge
is obtained of their habits which is likely to
chinch bugs, together with some of the
fungus which attacks them a destructive
disease. This vegetable parasite is being
extensively utilized in Kansas, bugs
affected with it being scattered broadcast
to spread contagion among their kind. In other
receptacles are combs OF humble bees and
wasps. which are being kept for the purpose Of
developing and breeding insect parasites that
have attacked the Larvae in the cells OF course,
the bumblebee is an animal of economic i'm
portance. inasmuch As it does a great deal of
useful work in the fertilizing of plants. Without
its aid In this way there would be no red clover.
For the study Of insects which attack water
vegetation a number OF aquaria are provided in
the breeding conservatory. The food plants
are put into these tanks. and the bugs are al
lowed to propagate under natura. conditions.
There are many Thousands Of species of water
insects. nearly all Of which become aerial
eventually, taking final shape as flies. A
familiar example il the mosquito, and another
is the dragon fly, the larval form Of which IL Q
horrid looking carnivorous worm found in
streams and ponds. Not the genius Of al en-
tomological Ovid could satisfactorily describe
the marvellous metamorphoses of insects.
In this breeding house for bugs are also open
boxes filed with EARTH in which young wheat
and other grains are growing. To mako these
little crops develop healthily is not the object
contemplated, and nearly every stalk reveals
upon examination the presence Of insects which
are feeding on them. In eaca box is only one
kind of plant and a single species Of bug, and.
where it is necessary to confine the latter or to
keep of other insects, . wooden framework
covered with gauze is put over the box. Besides
these there are so-called ''vivaria," which are
boxes with glass sides, wize-eauzs tops and
wooden bottoms holding zinc trays The
trays are fled with earth, and in the
center Of eaeh u soldered an M
right tube Of zile big enough 70 hold Q rood
sized bottle. In this bottle, which is kept filed
with water. the plant prsysd upon is put, and
the insects introduced 10 the visarium are per-
mitted to pursuA~ thar ordihnxy mefhoda of