Submitted to: Molecular Insect Science International Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 27, 2002
Publication Date: July 20, 2002
Citation: Roehrdanz, R.L., Levine, E., Degrugillier, S.S. 2002. Two different wolbachia types create a breeding barrier between populations of northern corn rootworm (Diabrotica barberi) in illinois [abstract]. Molecular Insect Science International Symposium Proceedings. Journal of Insect Science 2:17. p. 8. Technical Abstract: Wolbachia sp. are endosymbiotic bacteria that are widespread in Arthropods and are often associated with reproductive incompatibilities between infected and uninfected individuals. 16S rDNA primers detected Wolbachia in northern corn rootworms (NCR) from the eastern portion of their range with a Wolbachia +/- boundary in central Illinois. Portions of the Wolbachia ftsZ and wsp genes have been sequenced from several geographic locations. The 1058 bp ftsZ sequences from NCR are Type A Wolbachia and fall into two groups within that category. NCR Type I Wolbachia from eastern Illinois to Pennsylvania are nearly identical to Wolbachia from western corn rootworm (WCR)(<0.3%). NCR Type II Wolbachia from central Illinois differ by 3.1% from Type I and are nearly identical to a Wolbachia found in the European raspberry beetle (0.1%). The ~600 bp wsp sequences are also dramatically different. NCR Type I is identical to that from WCR, while NCR type II differs by 63 substitutions (>10%) and 15 indels. The boundary between these two very distinct strains of Wolbachia in adjacent geographical populations of NCR correlates with a previously observed mtDNA genetic boundary in eastern Illinois indicating that the two Wolbachias are incompatible and little if any introgression occurs between the two populations. There is currently no evidence that this boundary is being pushed in either direction. The boundary between the NCR Type II Wolbachia infected and uninfected insects appears to be less distinct and leaves open the possibility that Wolbachia infection is expanding westward in NCR. Also unresolved is the question of whether the eastern population of NCR might have acquired Wolbachia via horizontal transfer from WCR.