FOLIAR INSECTICIDES FOR CONTROL OF ASIAN CITRUS PSYLLID AND CITRUS LEAFMINER ON ORANGES,SPRING, 2010

ACP vectors the bacterium Candidatus Liberibacter asiaticus, causal organism of citrus greening disease or “Huanglongbing”. Feeding damage from CLM larvae facilitates the spread of citrus canker caused by Xanthomonas axonopodis pv. citri. Effective control measures are needed upon which to develop integrated management strategies against these pests and the associated diseases in Florida citrus. The experimental block at the Southwest Florida Research and Education Center, Immokalee, Florida consisted of 15-yr-old sweet orange ‘Valencia’ trees planted on double-row raised beds at a density of 132 trees/acre. Trees were irrigated by micro-sprinklers and subjected to conventional cultural practices. Trees had been recently hedged so new shoots for psyllid reproduction were plentiful. Nine treatments and an untreated check were randomly distributed across 4 replicates in 19 rows that included an unhedged buffer row between treated rows. Each replicate contained 10 five-tree treatment plots. Treatments were applied on 14 May 2010 using a Durand Wayland 3P-10C-32 air blast speed sprayer operating at 1500 RPM with 2 stainless steel TJet # 5 nozzles per side delivering 65 gpa. Post treatment evaluations were made on 17, 24, and 31 May. Ten to twelve shoots were tagged in each plot prior to treatment application. Ten randomly selected shoots per plot were collected and examined under a stereomicroscope in the laboratory to count ACP nymphs. Three fully expanded leaves per shoot were examined to count CLM larvae and mines. Adult ACP density was estimated from three central trees in each five-tree plot by counting insects falling on a clipboard covered with an 8 1⁄2 × 11 inch laminated white sheet placed under randomly chosen branches which were then struck 3 times with the PVC pipe to make a count for one “tap” sample. Four tap samples were conducted per tree. Data were subjected to ANOVA and means were separated using LSD (P = 0.05).