Control of Asian Citrus Psyllid and Citrus Leafminer with Cyantraniliprole, Cyclaniliprole and Flonicamid: Summer, 2015

Asian citrus psyllid (ACP) is the key pest of citrus in Florida, responsible for the spread of huanglongbing or citrus greening disease. Feeding damage from CLM larvae facilitates the spread of citrus canker. Insecticides are critical for suppression of these two pests. The experimental block at the Southwest Florida Research and Education Center consisted of 5-yr-old sweet orange “Hamlin” trees bud grafted to “US-802” (Citrus grandis × Poncirus trifoliata) planted at a density of 308 trees/acre. Trees were irrigated with microsprinklers and subjected to conventional cultural practices. Eight treatments and an untreated check, seven trees per plot, were randomly distributed across four replicates in four rows separated by untreated buffer rows according to a randomized complete block design. Treatments were applied on 21 Aug 2015 using a Durand Wayland AF100-32 air blast speed sprayer, operating at 1.9 mph and 300 psi equipped with #5, 4 and 3 two hole whirl John Bean ceramic nozzles delivering 80 gpa. Ten randomly selected shoots per plot were collected and examined under a stereoscopic microscope in the laboratory to count dead and live ACP nymphs at 4, 7, 12 and 19 days after treatment (DAT) and three fully expanded leaves on each shoot examined to count CLM larvae. Density of ACP adults was assessed at the same time and 25, 33 and 40 DAT on five trees per plot by taking two stem tap samples from each tree. A randomly chosen branch was struck three times with a short length of PVC pipe and individuals falling on a white plastic clipboard placed underneath were counted to make one tap sample. Data were subjected to ANOVA and means separated using LSD ( P  = 0.05).

Significantly more dead nymphs compared to the untreated check were observed at 4 DAT with treatments of Exirel + 435 oil, Cyclaniliprole + 435 oil and Cyclaniliprole + Beleaf + 435 oil ( Table 1 ). The latter treatment and Cyclaniliprole by itself at 22 and 27 oz/ac rates were also significant at 7 DAT. All treatments provided significant reduction of live nymphs through 12 DAT except Cyclaniliprole (16.4 oz/ac) and Beleaf (2.85 oz/ac) + 435 Oil at the last observation. Exirel, Cyclaniliprole, and Beleaf all applied with 435 Oil and Cyclaniliprole + Beleaf + 435 Oil provided significant reduction at 19 DAT. All treatments reduced CLM larvae through 19 DAT. Significant consistent reduction in ACP adults through 33 DAT was observed with Exirel + 435 oil, Cyclaniliprole + Beleaf + 435 Oil, Cyclaniliprole + 435 oil and Cyclaniliprole (27 oz/ac) except Cyclaniliprole + 435 oil at 25 DAT and Cyclaniliprole (27 oz/ac) at 12 and 25 ( Table 2 ). Cyclaniliprole at 22 oz/ac performed better with 435 oil than without with no effect of an increase in rate to 27 oz/ac. Beleaf provided better ACP control at 4.3 oz/ac compared to 2.85 oz/ac, both with 435 oil. No phytotoxicity was observed in any treatment. This research was supported by industry gifts of pesticide and funds.

Author notes