The Ocala evening star. [volume] (Ocala, Fla.) 1895-1943, 1910-05-20
CONTROL OF CITRUS PESTS
Spraying, Fumigating and Natural
Enemies Are Effective Means

While the control of citrus pests,
| except as applying to the citrus
thrips, grasshoppers and few mi
nor pests, is not a subject Of imme-
date Importance in Arizona, a brief
outline of the methods employed in
Florida and California should be of
general interest. 1t should also pro-
vide no little encouragement to cit
rus growers, especially those who
are now getting their first experience
in this line, for it should emphasize
the fact that Arizona's present ad-
vantages in not having serious pests
to require a perpetual tax on citrus
growers more than Offsets the trou-
bles which have to be contended
with in comparatively new citrus
growing regions.
Methods Of control of citrus pests
may be included under the divis-
ions of spraying. fumigating and the
use of natural enemies. Other meth
DDS are sometimes of Importance in
special cases, but in general they
should be considered only as ad-
junctS to the divisions mentioned In
the application of the various rene
dies, best results are secured when
the insects to be treated are thor
oughly understood. In spite of the
many years during which most of
the important pests have been under
Investigation from time to time, new
discoveries are continually being
made by Investigators and the rene
dies in each case are becoming better
adapted and better understood.
Spraying is the oldest general
remedy for citrus pests. In the case
of most citrus insects it is much
less satisfactory process of control
than fumigation. 1t usually requires
three or four applications of spray to
accomplish as much as would fumi
| cation, and economy in the long run
favors the latter process. In South
ern California a distillate oil spray
was used extensively a few years
ago, particularly against the black
and red scales, but much injury to
trees resulted and today compare
lively little spraying is done in citrus
groves in this section of the state.
In the northern part of the state
spraying is coming into use in Tulare
county in the control Of the citrus
thrips mixture composed Of to-
bacco extract, combined with weak
distillate oil emulsion is used, sew
eral applications during the season
| being required.
In Florida spraying has been used
to a considerable extent against cit
rus insects. In the case of scale in
sects, parasites or contagious dis
eases of the insect can usually be re-
lied upon to reduce the damage to a
point which makes spraying unprofit-
able. Sporadic outbreaks occur,
however, which result in severe
losses unless spraying or some other
direct remedy is reSOrted to.
Fumigation for citrus pests was
first practiced about 25 years ago.
Today this remedy costs the citrus
growers Of California an amount eS-
timated at more than a million dol
lars per year. During the year end
ing October 1 1906, in a single cOun-
ty, Los Angeles, according to the Off
cial reports of the county commits
sioner of horticulture, about $780,
600 was expended in fumigating.
In Florida fumigating is now COM
ing into general use and doubtless
will be extensively used in the flu
ture. The Florida method, first used
in the fall of 1907 in connection with
the white fly Investigations of the
United States Department of Agrl-
culture, has so simplified the process
that uniformity Of results can be at
tanned without previous experience.
This method consists of a fumigating
tent marked with graduated stripes
| for use in connection with a form of
dosage table adaptable for use
against any insect. With this as a
basis, it is a simple matter for an ex-
perimenter to determine the dosage
| requirement for any particular pest,
although previously it was imprac-
ticable to give any specific recon-
mendationS as to .'dosage. This
| Florida process is now coming into
general use in California, and &C
cording to the report of the ento-
| mologist of the United States De-
partment of Agriculture for 1909, 1t
| will eventually result in an annual
saving of from 80 to so per cent of
| the former cost of fumigation.
The so-called natural enemies of
citrus insect pests includes fungus
parasites, predacious insects and
parasitic insects. The fungus para
sites are partially effective in Flor
| ida and other gulf coast citrus grow
| ing regions, but experimental work
| has so far failed to show the prac-
| tica ability of increasing the efficacy of
these fungi by artificial means.
! Of the predacious insects, several
| imported species Of ladybugs are
| notably successful in California in
checking citrus pests and their value
| is inestimable. Control by means Of
| true parasites has not met with COM
| plete success so far in any instance.
| but important work in introducing
parasites of several scale insect
pests is now in progress under the
supervision of the state insectary at
| Sacramento.
The natural enemies of each of
| the more important citrus pests will
| be mentioned as these pests are indi-
vidually discussed in future circu-
| lars-A W. Morrill,, Arizona Horti-
! cultural Commission.
| WHAT EVERYBODY WANTS