Arthropod Management Tests 2013, Vol. 38
doi: 10.4182/amt.2013.D10
(D10) ORANGE: Citrus sinensis (L.) Osbeck, ‘Hamlin’ ASIAN CITRUS PSYLLID AND CITRUS LEAFMINER CONTROL IN ORANGES WITH LABELED AND EXPERIMENTAL INSECTICIDES: SUMMER, 2012 Philip A. Stansly University of Florida/ IFAS Southwest Florida Res. and Ed. Center 2685 State Road 29 North Immokalee, FL 34142-9515 Phone: (239) 658-3427 Fax: (239) 658-3469 Email:
[email protected] Jawwad A. Qureshi Email:
[email protected] Barry C. Kostyk Email:
[email protected] Asian citrus psyllid (ACP): Diaphorina citri Kuwayama Citrus leafminer (CLM): Phyllocnistis citrella Stainton Asian citrus psyllid vectors the bacterium Candidatus Liberibacter asiaticus, causal organism of citrus greening disease or “Huanglongbing”. Feeding damage from CLM larvae facilitates spread of citrus canker caused by Xanthomonas axonopodis pv. citri. Effective control measures are needed upon which to base integrated management strategies against these pests and associated diseases. The experimental block in a commercial grove near LaBelle, Florida consisted of 3-yrold sweet orange ‘Hamlin’ trees planted at a density of 130 trees/acre. Trees were drip irrigated and subjected to conventional cultural practices. Trees were flushing at the time of application and young shoots naturally infested with ACP and CLM. Eleven treatments and an untreated check were randomly distributed across 4 replicates in 8 rows using an RCBD. Replicates were divided into 12, twelve-tree plots and separated by a buffer row. Treatments were applied 31 Jul 2012 using a Durand Wayland AF100-32 air blast speed sprayer with the fan disengaged operating at 1.9 mph and 150 psi deploying two #6 and #5, (one side, top to bottom) John Bean ceramic nozzles delivering 30 gpa. Evaluations were made at 3, 7, 13, 21, 28, 35, 42 and 49 days after treatment (DAT). Ten randomly selected shoots per plot were collected and examined under a stereoscopic microscope in the laboratory to count ACP nymphs and three fully expanded leaves on each shoot was examined to count CLM larvae. Density of ACP adults was assessed from 6 of the 12 trees in each plot by counting adult insects falling on a white clipboard placed under randomly chosen branches which were then struck 3 times with a short length of PVC pipe to make a count for one “tap” sample. Data were subjected to ANOVA and means separated using LSD (P = 0.05). Infestation was heavy throughout the trial. Significant nymphal mortality compared to the untreated check was observed at 3 DAT in all treatments except Nexter alone or with M-pede and GWN 1708 + Oil or Portal + Oil (Table 1). Greatest suppression was seen with Lorsban 4E. These trends continued through 28 DAT with all treatments providing significant suppression of nymphs except for Dibrom or either treatment with Nexter or Portal + Oil at the last observation. All treatments provided significant reduction in ACP adults through 42 DAT (Table 2), except Nexter alone or with Mpede, Dibrome and GWN 1708 + M-pede. Most suppression at 28 DAT was seen with either formulation of Lorsban or Pyrinex. No significant treatment effect was observed at 49 DAT. All treatments except Nexter significantly reduced CLM relative to the untreated check at 3 DAT (Table 1). Reduction of larvae averaging more than 50% compared to untreated check was observed with Lorsban 4E, GWN 1708 + Oil or M-pede, GWN 1708 + Nexter + Oil and Portal + Oil. Addition of M-pede to Nexter did not improve ACP or CLM control. GWN 1708 applied with oil lasted longer and suppressed ACP more compared to its application with M-pede. No phytotoxicity was observed.
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Arthropod Management Tests 2013, Vol. 38
doi: 10.4182/amt.2013.D10
Table 1.
Treatments
Rate amt product/100 gpa or % v/v
Mean no. dead ACP nymphs/shoot
Untreated check none Dibrom 8E 16 oz Lorsban 4E 5 pts Lorsban Advance 5 pts Pyrinex 250 CS 1.2 gal Vulcan 5 pts Nexter 75 WP 9.9 oz Nexter 75 WP + M-pede 9.9 oz + 0.5% GWN 1708 + 435 Oil 30 oz + 2% GWN 1708 + M-pede 30 oz + 0.5% GWN 1708 24 oz + 6.6 oz + 2% + Nexter 75 WP + 435 Oil Portal 5 EC + 435 Oil 64 oz + 2%
3 DAT
Mean no. live ACP nymphs/shoot 3 DAT
0.33f 8.91cde 8.25de 17.63a 16.00ab 14.83abc 6.79def 2.67f 6.17def 10.58bcd 10.08bcd
10.75bcd
Mean no. CLM larvae/ 3 leaves/shoot
7 DAT
33.54a 38.83a 2.33de 9.60c 0.58e 0.93de 2.88de 2.00cde 1.13de 0.10e 2.33de 0.40de 14.29b 19.55b 11.67bc 25.08b 5.38cde 3.23cde 9.13bcd 8.65cd 8.04bcde 5.63cde
3.83cde
13 DAT
21 DAT
28 DAT
3 DAT
54.75a 32.73b 0.65e 1.48e 0.05e 4.60de 30.40b 18.03c 8.33de 11.58cd 5.03de
42.43a 26.38bc 6.50e 11.88de 11.65de 7.62e 31.10b 27.10bc 11.50de 23.85bc 18.68cd
25.97a 25.84a 10.00c 10.56c 11.84c 7.13c 24.63ab 24.75ab 7.63c 14.94bc 11.68c
4.00a 2.58bc 1.88bcd 2.58bc 2.25bc 2.71bc 3.13ab 2.67bc 0.67de 1.54cde 0.83 de
17.34abc
0.38e
6.05cde
6.55de 10.63de
Means in a column followed by the same letter are not significantly different (P > 0.05, LSD) Table 2. Treatments
Rate amt Product/100 gpa or % v/v
Untreated check none Dibrom 8E 16 oz Lorsban 4E 5 pts Lorsban Advance 5 pts Pyrinex 250 CS 1.2 gal Vulcan 5 pts Nexter 75 WP 9.9 oz Nexter 75 WP + M-pede 9.9 oz + 0.5% GWN 1708 + 435 Oil 30 oz + 2% GWN 1708 + M-pede 30 oz + 0.5% GWN 1708 24 oz + 6.6 oz + 2% + Nexter 75 WP + 435 Oil Portal 5 EC + 435 Oil 64 oz + 2%
Mean no. ACP adults/tap sample 3 DAT
7 DAT
13 DAT
21 DAT 28 DAT
35 DAT
42 DAT
2.13a 0.29cd 0.25cd 0.33bcd 0.08d 0.08 d 0.88b 0.79bc 0.13d 0.13d 0.33bcd
2.29a 0.29cd 0.00d 0.21cd 0.04d 0.25cd 1.25b 0.75bc 0.17cd 0.63bcd 0.50cd
2.08a 0.42de 0.08e 0.29de 0.04e 0.38de 1.67ab 0.71cde 0.83cd 1.17bc 0.63cde
5.13a 3.25b 0.58c 0.67c 0.79c 1.25c 3.87ab 4.00ab 1.50c 3.17b 3.13b
5.79a 4.29ab 0.75f 0.71f 0.54f 2.38cde 4.38ab 4.63a 1.38def 3.08bc 2.75cd
4.17a 3.63ab 1.71de 1.88cde 1.00e 2.38bcde 3.21abc 3.54abc 2.46bcd 3.21abc 2.42bcde
4.83a 3.00bc 1.71cde 2.33cde 1.42e 2.21cde 5.04a 4.71a 1.63de 3.88ab 2.96bcd
0.17d
0.04d
0.17de
1.17c
1.04ef
1.83cde
2.00cde
Means in a column followed by the same letter are not significantly different (P > 0.05, LSD)
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