Localization and dynamics of Wolbachia infection in Asian citrus psyllid Diaphorina citri, the insect vector of the causal pathogens of Huanglongbing

Wolbachia is a group of intracellular bacteria that infect a wide range of arthropods including the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. This insect is the vector of Candidatus Liberibacter asiaticus (CLas), the causal pathogen of Huanglongbing or citrus greening disease. Here, we investigated the localization pattern and infection dynamics of Wolbachia in different developmental stages of ACP. Results revealed that all developmental stages of ACP including egg, 1st–5th instar nymphs, and adults of both gender were infected with Wolbachia. FISH visualization of an ACP egg showed that Wolbachia moved from the egg stalk of newly laid eggs to a randomly distributed pattern throughout the egg prior to hatching. The infection rate varied between nymphal instars. The titers of Wolbachia in fourth and fifth instar nymphs were significantly higher than those in the first and second instar nymphs. Wolbachia were scattered in all nymphal stages, but with highest intensity in the U‐shaped bacteriome located in the abdomen of the nymph. Wolbachia was confined to two symmetrical organizations in the abdomen of newly emerged female and male adults. The potential mechanisms of Wolbachia infection dynamics are discussed. The interactions between Wolbachia and its Asian citrus psyllid (ACP) host may be beneficial in developing novel strategies for ACP and Huanglongbing management. Wolbachia, for reducing the transmission of Huanglongbing is a viable alternative because Wolbachia has high infection rates in ACP. So it is important to understand infection biology of Wolbachia in ACP first, including the infection level, and also the Wolbachia strain as well as the localization patterns in their psyllid hosts. This manuscript is the first to report the localization patterns of Wolbachia in ACP using the whole‐mount fluorescence in situ hybridization method.