Iowa state bystander. [volume] (Des Moines, Iowa) 1894-1916, 1913-12-19
SEARCH FOR INSECT
Australian Scientists Seek an
American Pest.
Worlds Search for an Insect That viii
Destroy tho Prickly Pear Cactus
Has Brought Australians to
the United States.

Has Brought Australians to
the United States.
Washington.-Two scientists from
Australia have arrived in America In
their worlds search for an insect that
will Prove destructive to the prickly
pear cactus. They have just consult.
ed with DR.. l.. o. Howard. entomolo.
gist Of the department Of agriculture,
and he has recommended two insects
which he thinks will furnish what
they have failed to find after a search
through India and southern Europe.
While the prickly pear cactus Is
considered such devastating pest IN
the Antipodes that every possible
measure is being taken to eradicate 1T
In the United States 1t has come to
be considered a crop having a high
feeding value. The plant has had a
varied history in this country. For.
merly it was cultivated particularly as
food for the insect that furnished
the coloring matter known as cochi.
neal. This insect was Of great econo'
mic Importance until there came the
decadence OF the cochineal industry.
Then. for a time. the cactus plants
were considered nuisance here, as
they are now considered in Australia,
as they occupied land that could be
used to advantage for valuable crops.
Thus, in few years the plant changed
in character from valuable one to a
weed while all insects that destroyed
1t, including the producer OF cochineal,
came to be considered beneficial mere
ly because they eradicated the weed.
Within recent years in the United
States there has been another revo-
luton in the attitude taken by hu.
mainly toward the prickly pear. 1t
has been recognized for many years
in the southern portion Of the United
States that the plant furnished food
supply for cattle during drought that
frequently prevented the starvation OF
large herds. Some years ago the ex-
pertinent station in Arizona began an
investigation Of the feeding value of
the prickly pear. 1t was soon found
that the plant had surprisingly high
feeding value. The greatest practical
difficulty in the use Of the plant for
forage was the spines, but 1t was
found possible to eliminate this diff
Guilty by smuggling the plants. or by
running them through machines which
chopped them into small pieces. Then
1t was discovered that the prickly
pear responded readily to cultivation.
The cultivation has been taken up on
a considerable scale and the insects
that prey on the plant again assume
a new role. They are now considered
as pests.
There are 324 species of insects
which are associated with the cactus
plant. These divide themselves nat.
urally into five classes. as follows:
Species injuring the plant. 80
Scavengers ....f5
Flower visitors ................ 4O
Species only incidentally associated
with the plant ................9 81
DR.. Howard has chosen two which he
considers particularly destructive to
the prickly pear, and these he has
recommended to the Australians.
The first is the longicorn beetle, a
hideous looking, wingless. robust,
shining black insect, which attacks
the cactus and does considerable in
jury by gnawing the edges of the
newly formed joints. This injury,
however. is insignificant in compari-
roots by the larvae of the beetle.
The other insect which DR.. How.
ard recommends is chelinidea With.
gera. 1t resembles the common
squash bug and attacks the joints OF
the prickly pear externally.
The scientists who hail from Aus
tralia are both from Brisbane, Queens
land. They are DR.. T. Harvey John.
ston Of the biology department Of the
University Of Queensland, and DR..
Henry Tyron. the government en-.
tomologist Of Brisbane. They will
leave Washington shortly for Texas,
Arizona and New Mexico. where they
will examine at close hand the work
of the two misunderstanding insects,
and If they find them satisfactory,
will consider the Introduction into
Australia as a beneficial insect OF two
misunderstanding pests Of the United
States