Hemolymph-associated symbionts: Identification of Delftia sp. in glassy-winged sharpshooters (Homalodisca vitripennis) and investigation into their putative function

The glassy-winged sharpshooter (Homalodisca vitripennis) is a large leafhopper native to North America that feeds on a wide variety of host plants including grapes, oleander, and citrus. GWSS is the primary vector of Xyllela fastidiosa, the causal agent of Pierce’s disease of grapevine, oleander leaf scorch, and citrus variegated clorosis. In recent studies, additional bacterial species have been identified within GWSS which may contribute to the insect’s survival and ability to adapt to the environment. Delftia sp., a gram negative bacterium which belongs to rRNA superfamily III or the â subclass of the Proteobacteria, was detected only in the insect’s hemolymph. Therefore, in this study, Delftia sp. associated with GWSS hemolymph was further identified through direct sequencing, and the relationship between this symbiont and its host was investigated. Delftia is a D-amino acid amidase-producing bacterium. D-amino amidases are increasingly being recognized to be important catalysts in the stereospecific production of D-amino acids. Delftia may be found in the hemocoel of the GWSS to hydrolyze D-amino acid amides to yield D-amino acid and ammonia which can perform as the insect’s chiral building blocks.