A comparison of sticky traps for monitoring Asian citrus psyllid (Diaphorina citri Kuwayama)

Six types of sticky card traps differing in color and trapping adhesive were evaluated for monitoring Asian citrus psyllid in citrus in the United States (Florida and Texas). We coded the six traps as ASYellow, GLYellow, RWYellow, ASACP, ASGreen and MGGreen. The ASYellow, GLYellow and RWYellow traps were a bright yellow color to the human eye but the yellow color of these traps varied in intensity. To the human eye, the ASACP traps were a lime-green color, the MGGreen trap was a fluorescent yellow-green color, and the ASGreen trap was a green color. Spectral reflectance measurements were taken to categorize the color (wavelength) spectrum of each trap. Percent reflectance in the green and yellow wavelength regions was similar among the ASYellow, GLYellow, RWYellow and ASACP traps. Three of the six sticky traps (GLYellow, RWYellow and MGGreen) were treated with a traditional gluey adhesive material. The other three traps were treated with No Mess Sticky Card™ adhesive, a hot-melted, pressure-sensitive adhesive material. Trapping studies were conducted in Florida and Texas during April–May comparing four of the traps and during September–October comparing all six traps. Data collected during April–May indicated there were no significant differences in numbers of adults captured on ASGreen, ASYellow, ASACP and GLYellow traps. In seven comparisons of all six traps during September–October, the GLYellow and RWYellow traps each captured significantly fewer adults in one comparison, the MGGreen trap captured fewer adults in two comparisons, and the ASGreen trap captured fewer in three comparisons. There was no evidence that any one of the six traps would be best at detecting psyllids when adult populations are scarce. There was no significant difference between the two adhesive materials with respect to numbers of adults captured on traps.