Investigating the Possibility of Wolbachia ‐ and Cardinium ‐Induced Parthenogenesis in Two Mite Species

In arthropods, thelytokous parthenogenesis, in which females develop from unfertilised eggs, is often associated with reproductive manipulation by endosymbiotic bacteria such as Wolbachia and Cardinium . This study investigated whether thelytokous parthenogenesis in two mite species, Amblyseius herbicolus (Phytoseiidae) and Czenspinskia transversostriata (Winterschmidtiidae), is induced by such endosymbionts. Four populations of A. herbicolus and one population of C. transversostriata from New Zealand were examined. The presence of Wolbachia and Cardinium was assessed using polymerase chain reaction (PCR), and the reversibility of parthenogenesis was tested through antibiotic treatment (tetracycline). Wolbachia was detected in two populations of A. herbicolus based on PCR amplification of the wsp gene, whereas Cardinium was not detected in either species. No males were produced following antibiotic treatment in either species. The short sequence fragments precluded strain‐level identification of Wolbachia , and subsequent assays failed to detect the bacterium consistently. These results suggest that parthenogenesis in A. herbicolus and C. transversostriata is unlikely to be induced by the endosymbionts examined and may instead be genetically determined. Further investigation of these species may improve understanding of the causes and mechanisms underlying this reproductive strategy.