Experimental infection with Rickettsiella phytoseiuli in adult female Dermacentor reticulatus (Ixodidae): an electron microscopy study.

Rickettsiella phytoseiuli naturally occurring in Phytoseiulus persimilis mites was cultivated in adult female Dermacentor reticulatus ticks. It demonstrates all six known developmental stages: dense, intermediate, bacterial, giant, crystal-forming and small dark particles. These stages of rickettsiae were found in salivary glands, Malpighian tubules, synganglion, ovaries, tracheal complex, haemolymph, fat body and alimentary tract. Rickettsiella phytoseiuli did not infect the Gené's organ. It multiplied in female ticks in a manner similar to that in the typical host mite, P. persimilis.