Attraction of a native Florida leafminer, Phyllocnistis insignis (Lepidoptera: Gracillariidae), to pheromone of an invasive citrus leafminer, P. citrella: evidence for mating disruption of a native non-target species.
We collected a native North American species, Phyllocnistis insignis (Frey & Boll) (Lepidoptera: Gracillariidae), in traps baited with a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal (triene) and (Z,Z)-7,11-hexadecadienal (diene), 2 components of the sex pheromone of the invasive citrus leafminer, P. citrella Stainton. No moths were caught in unbaited traps during 6 months of monitoring. We evaluated seasonal abundance of P. insignis by monitoring traps in citrus (Citrus spp.; Sapindales: Rutaceae) groves at 4 sites in southeastern Florida during 2012. Phyllocnistis insignis moths were found in pheromone-baited traps year round with a peak flight in May. In trials designed to evaluate mating disruption of P. citrella, application of triene (SPLAT CLMTM) disrupted trap catch of P. insignis during a 9 week period following treatment in spring (825 mg triene/ha), but not winter (750 mg triene/ha). In a second experiment, application of triene (837 mg/ha) and a 3:1 blend of triene and diene (840 mg triene+280 mg diene/ha, respectively) loaded onto rubber dispensers disrupted catch of male P. insignis during a 12 week period following treatment of 0.14 ha plots. Also, application of a 3:1 blend of triene and diene (764 mg+253 mg/ha, respectively) formulated in SPLAT CLM disrupted trap catch of male P. insignis during a 4 week period following treatment in a 66 ha plot. In a third experiment, application of blend (837 mg triene+278 mg diene/ha) reduced the incidence of trap catch to zero during a 16 week period following treatment of 0.87 ha plots. These data suggest that efforts to disrupt mating of P. citrella influence non-target populations of the congeneric leafminer species, P. insignis.