r's are known as arthropod reproductive manipulators!!!
they are known to cause cytoplasmic incompatibility (infected males make females have crappy broods), feminization, parthenogenesis, and male mortality in various species
one species of Rickettsia can be transmitted from infected planthoppers and have pathogenic effects on a FREAKING PLANT causing papaya bunchy top disease! that is so insane i can't quite wrap my brain around it... a disease that affects hoppers AND plants... that's... insane
taxonomy info:
Order Rickettsiales
Families 3: Anaplasmataceae and Rickettsiaceae (both of interest to us) and Holosporaceae (live with protista, not as much interest to us)
cacoseraph
Male-killing endosymbionts: influence of environmental conditions on persistence of host metapopulation
Dries Bonte, corresponding author Thomas Hovestadt, and Hans-Joachim Poethke