Wolbachia in Black Spiny Whiteflies and Their New Parasitoid Wasp in Japan: Evidence of the Distinct Infection Status on Aleurocanthus camelliae Cryptic Species Complex

SIMPLE SUMMARY: The Aleurocanthus camelliae cryptic species complex, which includes a number of morphospecies and/or haplotypes, is one of the growing biological issues, the underlying mechanism of which is still unknown. It is well-known that Wolbachia infection can produce significant mitochondrial divergence in insects, which may eventually result in cryptic speciation. Therefore, the diversity and phenotypic characteristics of Wolbachia natural infections in the A. camelliae cryptic species complex were investigated. Two morphospecies were found to have distinct infection statuses. A. spiniferus morphospecies was the uninfected population, while A. camelliae morphospecies was fixed for infections. The oscillation hypothesis is discussed in light of the current discovery of novel cryptic species of A. camelliae. This idea may offer insights into cryptic speciation, specifically on how specialization and host expansion have been observed among these species. Additionally, this research discovered a parasitoid wasp from the genus Eretmocerus in A. camelliae for the first time in Japan. ABSTRACT: Wolbachia, an alphaproteobacterial reproductive parasite, can cause profound mitochondrial divergence in insects, which might eventually be a part of cryptic speciation. Aleurocanthus camelliae is a cryptic species complex consisting of several morphospecies and/or haplotypes that are genetically different but morphologically indistinctive. However, little is known about the Wolbachia infection status in these tea and Citrus pests. Thus, this study aimed to profile the diversity and phenotypic characteristics of Wolbachia natural infections in the A. camelliae cryptic species complex. A monophyletic strain of Wolbachia that infected the A. camelliae cryptic species complex (wAlec) with different patterns was discovered. Whiteflies that are morphologically identical to Aleurocanthus spiniferus (Aleurocanthus cf. A. spiniferus in Eurya japonica and A. spiniferus in Citrus) were grouped into uninfected populations, whereas the fixed infection was detected in A. camelliae B1 from Theaceae. The rapid evolution of wAlec was also found to occur through a high recombination event, which produced subgroups A and B in wAlec. It may also be associated with the non-cytoplasmic incompatibility (CI) phenotype of wAlec due to undetectable CI-related genes from phage WO (WOAlec). The current discovery of a novel cryptic species of A. camelliae led to a discussion about the oscillation hypothesis, which may provide insights on cryptic speciation, particularly on how specialization and host expansion have been recorded among these species. This study also identified a parasitoid wasp belonging to the genus Eretmocerus in A. camelliae, for the first time in Japan.