SOIL DRENCH APLICATIONS FOR CONTROL OF ASIAN CITRUS PSYLLID AND CITRUS LEAFMINER, 2012

ACP and CLM are key citrus pests in Florida, attacking young flush and spreading two devastating diseases, huanglongbing (HLB) or citrus greening disease and citrus canker respectively. Young trees flush often and therefore require constant protection afforded by systemic insecticides applied as soil drenches. The objective of this trial was to test two modes of action novel for this use as alternatives to traditional neonicotinoids. It was conducted at the University of Florida Southwest Research and Education Center in Immokalee, Florida, on 1 year old ‘Hamlin’ orange trees spaced 10 ft apart within rows spaced at 22 ft or 198 trees per acre, although rates were calculated on an assumed density of 150 trees per acre. Seven treatments were assigned to 7-tree plots in an RCB design with 4 replicates. Weeds, debris and leaf litter were removed from beneath each tree prior to application. An 8 oz suspension of each product was applied 19 June to bare soil within 8 inches of the trunk using an EZ-Dose® sprayer operating at 45 psi. Percentage infestation of new shoots was estimated 25 Jun, 2, 9 Jul and 8 Aug on up to 10 newly emerged shoots from each of 5 centrally located trees in each plot using 14 X Coddington hand lens to note the presence of psyllid eggs or nymphs. On 31 – Jul, 8 and 21 Aug the adult psyllid population was evaluated by striking a randomly chosen branch 3 times with a length of PVC pipe on 5 centrally located trees in each plot to dislodge insects onto a white plastic clipboard to be counted as one tap sample. Ten shoots were removed from each plot on 17 Jul and 21 Aug 10 and taken to the laboratory to count eggs and nymphs under a stereomicroscope.