Provencher, L.M., Morse, G.E., Weeks, A.R., & Normark, B.B. 2005 Parthenogenesis in the Aspidiotus nerii Complex (Hemiptera: Diaspididae): A single origin of a worldwide, polyphagous lineage associated with Cardinium bacteria.. Annals of the Entomological Society of America 98(5): 629-635.

Notes: Aspidiotus nerii Bouché, the oleander scale, is a nearly cosmopolitan pest that attacks >100 families of woody plants. A. nerii has long been suspected of comprising multiple cryptic parthenogenetic and sexual species. We amplified and sequenced a 760-bp fragment of cytochrome oxidase 1 and 2 (COI-COII) from 59 individuals representing four laboratory stocks and 16 wild populations from four biogeographic regions (United States, several Mediterranean countries, South Africa, and New Zealand), along with three outgroup species. We also used polymerase chain reaction (PCR) to assay 92 individuals representing five laboratory stocks and seven wild populations for the presence of the intracellular bacteria Cardinium. We find three highly (>5%) divergent groups of mitochondrial DNA (mtDNA) haplotypes in A. nerii. Two of these are associated with males and not associated with Cardinium and are inferred to represent sexual populations. The other haplotype group is not associated with males, is associated with Cardinium, and includes laboratory stocks known to be parthenogenetic; this haplotype group is inferred to represent a parthenogenetic lineage. Although Cardinium is associated with the parthenogenetic lineage, a "curing" experiment that would demonstrate direct parthenogenesis induction by Cardinium has not been done. The parthenogenetic lineage is 5.5-7.3% divergent at COI-II from the closest sexual lineage and comprises five moderately divergent (=3.5%) haplotypes. This amount of mtDNA divergence within the parthenogenetic lineage may imply an ancient (=1 Mya) origin; however, the amount of amino acid sequence diversity within the parthenogenetic lineage is much greater than in the sexual sister-lineage, implying an elevated rate of nonsynonymous substitution in the parthenogenetic lineage. The highest haplotype diversity is found in New Zealand, and the closest outgroup is found in Australia, suggesting a possible Australasian origin of A. nerii.