USA Pheromone Center

Citrus Greening Disease

Alabama’s citrus, citrus nursery industry and home owner citrus trees are in danger of extinction from the invasive Asian citrus psyllid (ACP). The Asian citrus psyllid carries a bacterium (Candidatus Liberbacter asiaticus or africanum) which infects the citrus tree with Huanglongbing (HLB) or “citrus greening” disease which results in stunted growth, inedible fruit and the death of the tree in 2-5 years. The Asian citrus psyllid carrying the HLB bacterium and HLB diseased trees (lemon and satsuma) have been found by Alabama Ag and Industries personnel and reported to citrus industry growers and nursery owners on July 27, 2017 on Dauphin Island in Mobile County; and, in a satsuma tree on Bear Point in Baldwin County. The problem with this citrus disease is that host plants are grown in many backyards throughout the region not just in nurseries or in commercial groves and the disease is hard to detect. With rapid, extensive and timely public information as well as mobilization of the whole citizenry to detect and address the psyllid and diseased trees in home owner (dooryard) locations, all gulf coast counties in Alabama may be able to mitigate the devastating loss of citrus trees as experienced in Florida where large groves have suffered 70% losses. California and Texas are just now beginning to see the start of this disease. Because Florida, California and Texas have vastly greater resources to address this problem than Alabama, the need to be more innovative in mitigating the effects of this disease while buying time for a “cure” or the discovery of genetically resistant plants exists.

The goals of this project are to: (1) dramatically increase the speed of detection and analysis of the Asian Citrus Psyllid (ACP) itself and the citrus greening (CG), or HLB disease, of affected citrus trees in Baldwin, Clarke, Mobile, Monroe, and Washington counties, (2) dramatically increase the awareness of CG disease of the citizens of these counties and (3) dramatically increase the public’s education and participation in addressing this topic. This project could fund the necessary equipment and training to deploy pheromone traps and lures for the psyllids themselves, in order to determine the range and population of psyllids in the region. Detection of diseased plants in home owner locations would be facilitated by positive cooperation using resources through the University of South Alabama and the Environmental Toxicology Program.

Third, and perhaps more importantly, the existing Alabama Science in Motion (ASIM) program will be used to bring as many teachers and students into the research project as possible. The approach will include; ACP pheromone lures and sticky traps for ACP detection and monitoring of psyllids.  Once trained, teachers will be able to identify ACP and citrus greening of plants. Increased awareness by high school students because of direct involvement in the research project will increase the speed and awareness of the public of the presence of the psyllid and the disease.

Training for the high school teachers will be provided by USA Chemistry professors who are experts in each of the two project areas. The ETOX Master’s Degree program at USA will provide space, time and a graduate student assistant in support of the program. The results of each high school’s findings will be reviewed for scientific rigor by USA faculty and presented at USA research symposia.

Funds requested through this program will allow for the involvement of high school chemistry teachers and their students active in the statewide-funded program Alabama Science in Motion (ASIM). The ASIM program began in 1994 and was intentionally implemented to foster a partnership between universities and high schools. The overarching goals have been to provide high-tech laboratory experiences and professional training to area high school teachers and their students. Each participating school receives, throughout the year, complete lab kits to use in their classrooms at no charge. The SW region of ASIM (one of eleven in Alabama) consists of 32 high schools. The network established through this program, where members of the Department of Chemistry routinely interact with the teachers and students alike, through a number of on- and off-campus activities has the potential to reach out to 108 STEM teachers serving between 30-35K students on an annual basis. Combining the personnel with the footprint representing the Alabama counties of Baldwin, Clarke, Mobile, Monroe and Washington, the sampling and testing of trapped insects and potentially infected dooryard citrus trees representing just over 6,000 square miles of SW Alabama will offer the most rapid means of data collection and assessment for ACP. Communication of the project itself and project updates and results by means of USA resources provide a powerful avenue to enhance public awareness of this issue.

Contact Dr. David Battiste for Sampling Information

Asian Citrus Psyllid Sampling Form