Evaluation of the effects of light source and plant materials in psyllid trapping levels in the traps for citrus shipping containers

Authors: Mangan, Robert; Chapa, Deanna

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2012
Publication Date: 1/1/2013
Citation: Mangan, R.L., Chapa, D.L. 2013. Evaluation of the effects of light source and plant materials in psyllid trapping levels in the traps for citrus shipping containers. Florida Entomologist. Florida Entomologist 96(1): 104-111.

Interpretive Summary: Asian citrus psyllid is the vector for Huanglongbing (HLB), a deadly bacterial disease of citrus. Although most spread of the disease is through transport of infected trees, principally from infected nurseries, experiments in Florida showed that commercial citrus being transported from orchards to packing facilities were frequently contaminated with live Asian citrus psyllids. Areas currently free of HLB could, therefore, be infected both within and between states in the U.S. as well as from citrus transported into the U.S. from contaminated areas such as western Mexico. We tested a trapping system composed of light emitting diodes (LEDs) and sticky cards which are commercially available for monitoring pests in closed containers. Tests were run in environmental chambers in our laboratory with temperature and humidity settings similar to those in non-chilled trucks. Results showed that traps with 2 LEDs captured more psyllids than traps with 1 LED which captured more than traps with no LEDs. In addition, the traps usually captured a high percentage (>90%) of the psyllids in the container. The traps were successful in trapping the psyllids in containers containing fruit, nursery trees, or no plant material. We propose that introduction or spread of HLB through transport of psyllids in commercial shipments could be reduced or prevented by monitoring shipments by use of these traps in the trailer loads.

Technical Abstract: The Asian citrus psyllid (ACP), the principle vector for Huanglongbing (HLB), has been reported to be transported in truckloads of oranges in Florida. Citrus, especially Key limes and lemons, are shipped to the U.S. from Mexican states that are heavily infested with HLB and live, infected psyllids could spread the disease in orchards near inspection facilities or packing houses where trucks are unloaded. Experiments reported here tested the use of a sticky trap with light emitting diode(s) (LED) to detect possible contamination of fruit loads by ACP in containers. Experiments were performed in chambers maintained at temperatures and humidity similar to those in truck trailers arriving from Mexico. The effects of light intensity (no LEDs, 1 LED, 2 LEDs) and plant material (no material, fruit only, trees and fruit) were measured and analyzed to determine the relative efficacy of the trap types and to the role of plant material a system in detect the ACP. Results showed that ACP could survive in containers with no plant material, fruit only, or fruit plus plant material. The majority of the insects were recovered from the traps with smaller psyllid numbers surviving or dying in the container. The traps with 2 LEDs were most effective, followed by 1 LED traps, then those with no lights. These results showed that the psyllids in these chambers were more likely to be trapped than to survive or die in the chamber. Thus, sticky traps with LEDs as a light attractant can be effective means to detect psyllid contamination in citrus shipping.