Population biology of cytoplasmic incompatibility: maintenance and spread of Cardinium symbionts in a parasitic wasp.

摘要: Bacteria that cause cytoplasmic incompatibility (CI) are perhaps the most widespread parasites of arthropods. CI symbionts reproductive failure when infected males mate with females either uninfected or a different, incompatible strain. Until recently, was known to be caused only by α-proteobacterium Wolbachia. Here we present first study population biology Cardinium, recently discovered symbiont in Bacteroidetes causes parasitic wasp Encarsia pergandiella (Hymenoptera: Aphelinidae). Cardinium occurs at high frequency (∼92%) field. Using wasps were collected field, measured parameters crucial for understanding how spreads and is maintained its host. exhibits near-perfect rates maternal transmission, strong reduction viable offspring crosses, induces fecundity cost, producing 18% fewer 4 days reproduction. We found no evidence paternal transmission horizontal through parasitism an conspecific. No cryptic parthenogenesis found, nor sex allocation influenced infection. incorporated our laboratory estimates into model dynamics. The predicts stable equilibrium, similar what observed Interestingly, also threshold invasion (20% 24% females), below which infection expected lost. consider this may overcome, focusing particular on sensitivity models costs. Overall results suggest factors governing dynamics Wolbachia strikingly similar.