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University of Florida -'ARC
Mimeo Report ARC-FL76-2
Research Progress Report on Chemical Control of
the Citrus Blackfly, Aleurocanthus woglumi Ashby
James A. Reinert IRAR
University of Florida, ARC, IFAS
Ft. Lauderdale, Fla. AUG14 i978
September 10, 1976
i.F.A.S. Univ. of Florida
The citrus blackfly Aleurocanthus woglumi Ashby, is potentially one
of the most economically important pests of Florida Citrus. It is well
established in Mexico, Jamacia, Cuba, Panama, Costa Rica, the Bahamas,
Haiti, and parts of Texas and is primarily a pest of citrus. On
January 28, 1976, it was detected in Ft. Lauderdale, Fla., and now in-
fests portions of Broward, Palm Beach, and Dade Counties.
Research was initiated at the Agricultural Research Center in Ft.
Lauderdale to develop a chemical program for either eradication or
management of this pest. Effort is being directed to develop techniques
and strategies in various environmental situations; homeowner yards,
wholesale and retail nurseries, commercial citrus groves, and non-crop
The following summarizes the experiments completed, or in progress,
for control of citrus blackfly by chemical insecticides.
Experimental Results: ... ...
1. One experiment was conducted to compare different methods of
applying malathion." In this study a truck-mounted ULV and a hand-held
electrical powered mist blower were compared with foliar sprays applied'
with truck-mounted spray units. Five trees were treated with each method
and the larval (2nd and 3rd instar) mortality was-evaluated at weekly
intervals post-initial treatment. Treatments were reapplied weekly for
a total of three treatments.
Note in Table 1 that significant control was achieved by the foliar
sprays. The mist blower applications gave some control at the 1.25 Ib
AI/100 gal rate but apparently failed at the 2X rate. This discrepancy
cannot be explained. :The use of ULV at the rate presently used for
mosquito control provided no control in this test. All data in Table 1
were adjusted by Abbott's Formula to the untreated checks.
Percent control of citrus blackfly by malathion applied by
Treatment Lb AI/100 Weeks after initial
1 2 3
Foliar spray 1.25 73 89 75
Mist Blower 1.25 43 89 -47
Mist Blower 2.5 33 0 23
ULV 0 0 0
* 2 gal maximum flow rate/hour simulateda treatments ior
Adjusted by Abbott's Formula.
2. A second experiment evaluated deep-root soil injection as a
method for treating with a systemic insecticide to control the citrus
blackfly. Dimethoatle (CygonR) was metered into the root zone of each
tree at rates of 2-16 gm AI/inch of trunk:.diameter. Four trees were
treated with each rate of dimethoate. Table 2 shows that all rates of
the insecticide provided some control of the citrus blackfly larvae
(based on mortality of 2nd and 3rd instars) at 2 weeks. The 8 and -16
rates provided 95 and 91% control, respectively. The degree .of control
was greatly reduced at 3 weeks when populations .were reevaluated.
Table 2. Control of citrus blackfly by soil injection of dimethoate.
gm AI/ % Control*
Chemical in. diam. 2 Wk 3 Wk
Dimethoate 2 44 49
Dimethoate 4 29 32
Dimethoate 8 95 9
Dimethoate 16 91 33
Control represents 2nd and 3rd.instars
Adjusted by Abboft's Formula
3." A third study was made to evaluate 9 insecticides by foliar dip.
Five citrus terminals were treated with each insecticide by dipping
each terminal into the spray solution; this method simulated a foliar
drench spray treatment-with complete coverage.
The data in Table 3 show that acephate (OrtheneR), endosulfan (ThiodanR),
SD-43775, diazinon, dimethoate, malathion, FMC-33297, methidathion (SupracideR),
and oxydemetonmethyl gave control of the citrus blackfly when the infested
terminals were immersed into each spray solution. Based on these data, it
appears that several insecticides are highly effective in controlling this
pest, if adequate coverage is obtained.
Table 3.. Percent control of citrus blackfly following dipping
of infested terminal branches into different insecti-
S % Mortality
AI/100 1 Wk 2 Wk
Chemical Gal (lb) L P L P
Acephate .0.5 98 100 100 100
Endosulfan 0.5 97 100 100 99
SD-43775 0.5 50 49 100 98
Diazinon 0.5 99 99 100 97
Dimethoate. 0.5 100 99' 99 100
Malathion 1.25 99 95 99 99
FMC-33297* 0.5 95. .64 95 79
Methidathion 0.5 98 98 85 90
Oxydemetonmethyl 0.5 83 99 83 98
Check .0 25 32 03- 14
L = 2nd and 3rd instars
P = pupae
4.-. A fourth -experiment was-conducted-to.compare-malathion foliar
spray with mist blower applications of malathion, acephate, chlorpyrifos
(DursbanR), naled (DibromR), and pyrethrin (PyrellinR). Six trees were
treated with each chemical preparation. Treatments were applied weekly
for 3 weeks. Though the rates may appear to be much higher for mist
blower treatments, the actual amount on material applied per tree was
far less than that applied by the foliar spray of malathion.
Table 4 shows that mist blower treatments of acephate and chlorpyrifos
were highly effective in controlling citrus blackfly larvae. .An added
bonus to both materials was the high pupal mortality obtained at 2 weeks
post-initial treatment. Malathion did not provide nearly as good control
as either of these materials. It is important to point out that there
was essentially no difference in control provided by the 2 methods of
application for malathion.
Table 4. Comparative control** of citrus blackfly by different
insecticides applied by mist blower.
AI/100 1 Wk 2 Wk /(
Chemical Gal (lb) L P L P P /
Acephate 2.5 91 82 100 97 97 Y
Chlorpyrifos 2.5 82 .69 98 94 ? '3
Malathion* 1.25 67 58 87 64 f 3
Malathion 2.5 70 69 87 61 7 919
Naled 5.0 49 63 77 65 71 7/
Pyrethrin 0.1 0 6 0 -0 7
*Applied as foliar spray
**Adjusted by Abbott's Formula
L = 2nd and 3rd instar
P = pupae
5. A soil drench experiment was initiated using nursery citrus in
containers. -Trees approximately 5 feet tall were placed under infested
trees in the field for 4 days to obtain a heavy oviposition on them.
They-.were then held in quarantine for 2' weeks at which time eggs began
hatching.. Groups of 5 plants each were then soil drenched with either
5 or 10 lbs AI/A of acephate, aldicarb (TemikR), dimethoate, oxamyl
(VydateR), oxydemetonmethyl, or azinphos-methyl (GuthionR). Populations
were evaluated at 1, 2, and 3 weeks following application;
Table 5 shows that-acephate, dimethoate, and aldicarb provide control
of this pest when container grown-plants are treated by soil drench.
Oxydemetonmethyl, azinphos-methyl or oxamyl do not provide control as
soil drenches.- This method of treatment appears to be an acceptable
means of controlling citrus blackfly on container grown citrus trees.
Percent control of citrus blackfly on container grown
citrus trees treated by soil drench.
AI/A % .Control of Larval*
Chemical (lb) 1 Wk 2 Wk 3 Wk
Acephate 5 34 94 95
10 85 94 100
Dimethoate 5 56 -7 71
10 91 96 99
Aldicarb** 5 12 59 89
10 '60 95 100
Oxydemethonmethyl 5 6 13 0
10 9 0 14
Azinphos-methyl 5 8 0 0
10 1 0 0
Oxamyl 5 13 0 16
10 32 10 14
* Adjusted. by Abbott's Formula
**Applied as a granular formulation.