Huanglongbing (HLB), also known as citrus greening, is a devastating disease that has crippled citrus industries worldwide. Spread primarily by the Asian citrus psyllid, the disease causes tree decline, poor fruit quality, and dramatic yield losses. Traditional pest control strategies have relied on broad-spectrum insecticides and antibiotics, raising concerns over environmental contamination, resistance development, and diminishing returns. Moreover, existing “attract-and-kill” devices are labor-intensive and struggle to compete with the crop itself. Due to these limitations, there is an urgent need to develop integrated, eco-friendly solutions that target the vector effectively and sustainably.
In a new study (DOI: 10.1093/hr/uhae311) published in Horticulture Research (November 6, 2024), researchers from the University of Florida and international collaborators unveiled a living attract-and-kill system powered by a modified citrus tristeza virus. The virus was engineered to express a triple gene construct targeting both the plant and its pest. When delivered into citrus trees, the virus enhances the plant’s attractiveness to psyllids while simultaneously silencing genes critical to insect development, creating an elegant self-contained defense mechanism against HLB spread.
The research team developed a recombinant virus carrying three gene fragments: tPDS from citrus and tAwd and tWnt from Diaphorina citri. Silencing PDS triggers a photobleached plant appearance and alters leaf chemistry, increasing visual and olfactory cues that attract psyllids. Once the insects feed on these plants, the viral RNA targets and silences their Awd and Wnt genes—key regulators of wing formation and physiological function—resulting in malformed wings, reduced fertility, and drastically shortened lifespans.
In controlled trials, psyllids showed a marked preference for infected plants, but their populations collapsed over two generations due to developmental defects and high mortality. Wing deformities hindered mobility and flight, likely impeding pathogen transmission. The effect was further confirmed by applying sap from infected plants directly to psyllids, which caused rapid mortality. Remarkably, the engineered virus remains stable in the plant for extended periods, making the system low-maintenance and long-lasting.
“This technology turns the crop itself into a smart defense system,” said Dr. Nabil Killiny, senior author of the study. “Instead of relying on chemicals or traps, we let the plant attract the insect—and then eliminate it from the inside. It's precise, it’s sustainable, and it’s scalable.” Dr. Killiny emphasized that this method not only reduces pest pressure but also supports biodiversity by minimizing harm to beneficial insects and the environment.
The engineered virus could be deployed strategically in citrus groves to suppress psyllid populations and slow the spread of HLB. In regions facing early-stage outbreaks, border rows could be selectively inoculated to serve as living traps. In severely affected areas like Florida, widespread deployment of replacement trees could help restore productivity. By embedding pest control directly in the crop, this innovation eliminates the density limitations of artificial devices and reduces the need for chemical sprays. The platform may also be adapted to other pest-crop systems, ushering in a new era of “living technologies” for sustainable agriculture.
###
References
DOI
10.1093/hr/uhae311
Original Source URL
https://doi.org/10.1093/hr/uhae311
Funding information
This project was supported by the Emergency Citrus Diseases Research and Extension grants program, Award number 2020-70029-33177 from the USDA National Institute of Food and Agriculture.
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.