Symbiotic microbial studies in diverse populations of Aphis gossypii, existing on altered host plants in different localities during different times

Complex interactions between symbiotic bacteria and insects ultimately result in equilibrium in all aspects of life in natural insect populations. In this study, abundance of principal symbiotic bacteria was estimated using qPCR in 1553 individuals of aphids, Aphis gossypii. Aphids were sampled from primary and secondary host plants-hibiscus and cotton. Hibiscus aphids were collected from 24 different locations in April, September, and November, whereas cotton aphids were collected between 2015 and 2017 from areas with wide variations in climatic conditions. About 30%-45% aphids were recorded with the most dominant symbiont, Arsenophonus. The other symbionts were in low frequency, and about 7% of aphids were noted with Hamiltonella, Acinetobacter, and Microbacterium, and 3% of aphids were verified with Serratia and Pseudomonas. Aphids infected with Hamiltonella, Arsenophonus, and Serratia can influence Buchnera densities. Hamiltonella has positive interaction with densities of Arsenophonus and Serratia. Almost 100% coinfection of Hamiltonella and Arsenophonus was detected in Xinxiang aphids and 50% coinfection was reported in aphids from North China, while no coinfection was detected in Hainan aphids. These findings describe the prevalence pattern and richness of core community of symbiotic bacteria in naturally occurring populations of A. gossypii and provide new insights for the study of symbiotic bacteria.