Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1913-05-17
CLEARING UP ENToMol oGIcAL
MISCONCEPTIONS. =.

i Editor Honolulu Star Bulletin.
Sir:-In letter in the Bulletin
Of May IS. the origin Of the Mediter-
ranean fruit-fiy in Honolulu is ascribed
| TO the Introduction of pest" for
lantana by the Territorial Board of
Agriculture. your correspondent stat,
| ing that the pest" introduced for Ian
tana has now become the Mediter-
ranean fly depriving US of our home
! fruits He further decries the intro
| duction of parasites Tor pests" as he
calls them into this country to kill
of the Mediterranean fly. -: ....<
This serves to illustrate the general.
or at least too prevalent misconcep-
! ton in regard to insect pests, and
| parasites and makes occasion for a
simple explanation of the terms. =. =.
| Insect pests" perhaps really needs
no explanation, as so well known 1t
refers to any and all insects that serve
/ TO injure any vegetable. fruit, field or
ornamental crops or plants grown by
man; that attacks or annoys man an
his domesticated animals: or are in
strumental in transmission and spread
| ing Of disease. -
An insect parasite" on the other
hand is an insect wnicn attacks an
other insect in one or another of its
stages of development, cO-eXists with
its host for a time and finally kills it.
IL does this irrespective of whether
the insect attacked is pest or not.
Among insects in the state of nature,
the usual situation is that each species
of insect has one or more parasites,
and often the parasite attacks but the
one species of insect and will not I'M
der any circumstances attack any
other Many insects. that are pests"
have become so by reason of their hay-
ing succeeded in getting away from
their parasites, going to some other
country where no parasite would at
tack them and prevent them 1ncreas-
ing to such numbers as to be consid-
cred pests"
Compared to its size, there is no
place i'm the world where SO much has
been done in hunting out and the in
PRODUCTION of the special parasites Of
insect pests as in Hawaii. Many spe-
cies have been introduced from Vari-:
Gus parts of the world, some have
failed to become established here, but
a large number of them have succeed
ed in becoming established and have
been spread throughout the Islands.
and are doing their good work of
checking insect pests. unseen by peo-
pie generally as they are mostly so
small and obscure as to escape notice,
but that fact does not discourage them
from keeping up their warfare Oh the
pests.
In no case has any OF these para
sites introduced by the entomologists
changed it's habit and became a pest.
An insect adapted to be parasitic on
other insects can not become vege-
table or fruit pest It cannot alter
it's anatomical structure. which would
be necessary for such a change in
habits.
Another thing about insect para
sites is that they never exterminate
pest that they may be preying on, and
they have not in every case where IN
troduced here been able to check the
insect preyed uDon so that 1t ceased
to be a pest The fact that parasites
are present does not furnish any rea-
son for not employing other methods.
where possible, or necessary in fight
ing an insect pest. Let the parasites
do their work but supplement- this
work in any way possible by other
means
Now in regard to the insects intro
duced by the Board of Agriculture OF
feed upon lantana, perhaps enough has
been said in explanation of them and
their habits at previous times, but it
may not be too much repetition if the
facts in regard to them are again
stated. ~ =.
Professor Koebele made Thorough
study of the insects preying exclusive
.ly on lantana in Mexico, to ascertain
which could really be introduced here
to serve to check this plant: Eight
species of insects were introduced ana
became established and spread all
over the islands OF these insects, the
maggots of the little black seed-tly de-
stroy the seeds in the growing Der
ries; the larvae of two species OF
moths feed in the flower clusters, thus
helping to prevent the formation OF
berries; the larvae of another moth :
mine the leaves, thus causing them to
become ineffective in the service OF
the growing plant; a small bug feeds
on the underside of the leaves, caus-
ing them to die and fall off; the larvae
of two species Of butterfly feed on the
flowers; a gall fly produces large
swellings or gals on freshly growing