Parasitoid-mediated horizontal transmission of Rickettsia between whiteflies

Authors: LIU, YUAN - Chongqing University; HE, ZI-QI - Guangzhou University; WEN, QIN - Guangzhou University; PENG, JING - Guangzhou University; ZHOU, YU-TONG - Guangzhou University; MANDOUR, NASSER - Suez Canal University; McKenzie, Cindy; Ahmed, Muhammad; BAO-LI, QIU - Chongqing University

Submitted to: Frontiers in Cellular and Infection Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2022
Publication Date: 1/4/2023
Citation: Liu, Y., He, Z., Wen, Q., Peng, J., Zhou, Y., Mandour, N., Mckenzie, C.L., Ahmed, M.Z., Bao-Li, Q. 2023. Parasitoid-mediated horizontal transmission of Rickettsia between whiteflies. Frontiers in Cellular and Infection Microbiology. https://doi.org/10.3389/fcimb.2022.1077494.
DOI: https://doi.org/10.3389/fcimb.2022.1077494

Interpretive Summary: Parasitic wasps are used in whitefly biological control. This study reveals that one of the most common parasitic wasps of whitefly can pick a bacterial symbiont called Rickettsia from an infected whitefly, retain in its body for at least 48 hours and can then transfer to other uninfected whiteflies. Bacterial symbionts play an important role in modifying whitefly biology. Our study points out an unintended impact of parasitic wasp in whitefly biological control.

Technical Abstract: Intracellular bacterial endosymbionts of arthropods are mainly transmitted vertically from mother to offspring, but phylogenetically distant insect hosts often harbor identical endosymbionts, indicating that horizontal transmission from one species to another occurs in nature. Here we investigated the parasitoid Encarsia formosa- mediated horizontal transmission of the endosymbiont, Rickettsia between different populations of whitefly Bemisia tabaci MEAM1. Rickettsia was successfully transmitted from the positive MEAM1 individuals (R+) into E. formosa and retained at least for 48 h in E. formosa. FISH visualization results revealed that the ovipositors, mouthparts and digestive tract of parasitoids get contaminated with Rickettsia. Randomly occurred non-lethal probing of Rickettisia negaive (R-) MEAM1 nymphs by these Rickettsia-carrying E. formosa resulted in newly infected B. tabaci individuals, and the vertical transmission of Rickettsia within the recipient feamles can be remained at least up to F3 generation. Further phylogenetic analyses revealed that Rickettsia had high fidelity during the horizontal transmission in whiteflies and parasitoids. Our findings may help to explain why Rickettsia bacteria are so abundant in arthropods, and suggest that in some insect species that shared same parasitoids, Rickettsia may be maintained in populations by horizontal transmission.