Wild sources for host plant resistance to Bemisia tabaci in watermelon: insights from behavioral and chemical analyses

Authors: MCKENIE-REYNOLDS, PETRINA - Oak Ridge Institute For Science And Education (ORISE); OWOLABI, ISIAKA - University Of Georgia; BISWAS, ANJU - Oak Ridge Institute For Science And Education (ORISE); Read, Quentin; BURKE, GAELEN - University Of Georgia; Levi, Amnon; Simmons, Alvin

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2025
Publication Date: 9/19/2025
Citation: Mckenie-Reynolds, P., Owolabi, I., Biswas, A., Read, Q.D., Burke, G.R., Levi, A., Simmons, A.M. 2025. Wild sources for host plant resistance to Bemisia tabaci in watermelon: insights from behavioral and chemical analyses. Crop Protection. 199:107411. https://doi.org/10.1016/j.cropro.2025.107411.
DOI: https://doi.org/10.1016/j.cropro.2025.107411

Interpretive Summary: Whiteflies are serious insect pests that feed, as well as transmit plant viruses, in many crops, including watermelon. Although the use of pesticides is the most common control tool for whiteflies, this method is not sustainable. Developing plants that have natural resistance to whiteflies could provide a reduced need for insecticides in crop production. Among 13 wild watermelon types tested, the whiteflies were less attracted to the odor of these plants and they laid fewer eggs as compared with the tested commercial watermelon plants. The oder from the wild watermelon plants contained high levels of certain chemicals (phenol derivatives and sesquiterpenes) that were associated with making the plants less attractive to the flying whiteflies in their search for plants to feed on. The findings from this research will help researchers in developing watermelon cultivars that have resistance to whiteflies and other pests.

Technical Abstract: Whitefly infestations, primarily caused by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), are problems in watermelon production. This pest has led to severe yield losses and an increased reliance on chemical pesticides by growers. In this study, genotypes of the desert-watermelon Citrullus colocynthis (L.) Schrader and the cultivated watermelon (C. lanatus) were evaluated for resistance to B. tabaci using oviposition and vertical Y-tube olfactometer assays. In addition, gas chromatography-mass spectrometry (GC-MS) analysis of plant volatiles was conducted. Among 13 C. colocynthis accessions tested, Agricultural Research Organization-Israel Gene Bank Accession-2010 (ARO-2010) and United States Plant Introduction (PI)-386024 received the least incidences of oviposition, while PI 386019 and PI 688367 demonstrated reduced attraction of adult whiteflies to plant volatiles as compared with the susceptible cultivar ‘Sugar Baby’. GC-MS analysis identified phenol derivatives and sesquiterpenes as dominant volatiles in the C. colocynthis resistant accessions. The volatiles of the C. colocynthis PI-542616 contain 97.8% phenol, 2,2’-methylenebis[6-(1,1-dimethylethyl)-4-ethyl]. The volatiles of the C. colocynthis PI-386019 exhibited the highest concentration (12.0%) of the antioxidant 2,2’-methylenebis-(6-tert-butyl)-4-ethylphenol acetate. These findings help elucidate the biochemical and volatile-mediated whitefly-resistance mechanisms in C. colocynthis. By integrating resistant germplasm into integrated pest management (IPM) strategies, this research advances sustainable watermelon production.