Bacteriocyte
Guides
Pachypsylla venusta
Hackberry Petiole Gall Psyllid
Pachypsylla venusta is a hackberry-associated psyllid that forms distinctive woody galls on hackberry leaf petioles. Adults are small (3.5-4.5 mm), resembling tiny cicadas with piercing-sucking mouthparts. The species maintains an obligate mutualism with Carsonella ruddii, a γ-Proteobacterium with the smallest known cellular genome (160 kb), housed within specialized 16-ploid bacteriocytes. While galls are visually conspicuous, they cause minimal harm to host trees.