Bacteriome of Philaenus spumarius genitalia and its implication on insect’s host reproduction

Abstract: Philaenus spumarius has been increasingly studied in the last years as a result of being one of the principal vectors of Xylella fastidiosa in the European Union. X. fastidiosa is a phytopathogenic bacterium that infects several economically important crops, and for which there is no cure. One possible option to contain the spread of X. fastidiosa is through the management of its vector, P. spumarius. The natural microbiota population of an insect has important roles in the insect life, such as in immunity, feeding and reproduction. Thus, the characterization and exploitation of the insect-microbial associations can contribute to the control of disease vectors. Here, the bacterial community associated to the genitalia of P. spumarius was evaluated using both culture-dependent and -independent (metagenomic) approaches. The ability of the cultivable bacterial in altering the reproductive potential of their hosts, was additionally evaluated by using an insect model, the Drosophila melanogaster. Overall, 245 bacterial operational taxonomic units (OTUs) were identified, being 174 found in females and 244 in males. Cutibacterium was the most predominant genera found in the genitalia of both males and females. A high number of genera were found to be restricted to either male (28) or female (37), being only around 48% of genera shared among the two genders. A total of 5 cultivable bacterial were screened for their impact on D. melanogaster fitness, along three generations. Most of the tested bacterial reveal to significantly influenced the number of dead larvae, number of pupae, number of females, and size of the body and wings of both male and female, but with variable effects. Some bacteria were able to reduce the size of the body and wings of males; while others showed to promote the larvae dead, pupae and female number, and to increase the size of the body and wings of both males and females. Implications of these findings for P. spumarius management will be discussed.