Phylogeographic and endosymbiont analyses of Pezothrips kellyanus reveal the Australian source populations of invasions elsewhere

Tuesday, November 15, 2022

3:42 PM – 3:54 PM PT

Location: Vancouver Convention Centre, Meeting Room 212

Presenting Author(s)

Alihan Katlav

Postdoctoral Research Fellow
Hawkesbury Institute for the Environment
Richmond, New South Wales, Australia

Co-Author(s)

DN

Doung T. Nguyen

Elizabeth Macarthur Agricultural Institute
Narellan, New South Wales, Australia
JC

Jodie Cheesman

Queensland Department of Agriculture and Fisheries
Mareeba, Queensland, Australia
AC

Asha Chhagan

Plant and Food Research
Auckland, Auckland, New Zealand
LJ

Lisa Jamieson

Plant and Food Research
Auckland, Auckland, New Zealand
SL

Stewart Learmonth

Department of Primary Industries and Regional Development
Manjimup, Western Australia, Australia
AR

Alexander Robertson

Hawkesbury Institute for the Environment
Richmond, New South Wales, Australia
Piotr Trebicki

Research Scientist
Agriculture Victoria Research
Horsham, Victoria, Australia
JC

James M. Cook

Professor
Hawkesbury Institute for the Environment
Richmond, New South Wales, Australia
MR

Markus Riegler

Associate Professor | Higher Degree Research Director
Hawkesbury Institute for the Environment
Richmond, New South Wales, Australia

Kelly’s citrus thrips, Pezothrips kellyanus (Bagnall), an Australian-native significant pest of citrus, is invasive in New Zealand and Mediterranean countries. It is suggested to originate from rainforest biomes of eastern Australia, yet the exact Australian source of the invasive populations remain elusive. This species has two maternally inherited bacterial endosymbionts, Cardinium and Wolbachia. Both cause independently cytoplasmic incompatibility, and thereby invade host populations. According to mitochondrial COI gene sequences, the invasive populations in New Zealand and Mediterranean countries have a single but different haplotype, respectively, indicative of two independent invasion events. However, all individuals of invasive populations lack Wolbachia, raising questions why Wolbachia is absent from the invasive ranges. Using phylogenetic, haplotype network and endosymbiont prevalence analyses we detected populations with these two haplotypes in Victoria, all with Cardinium but without Wolbachia. This suggests that Victorian populations may have been the source of invasions, and the absence of Wolbachia in invasive populations might be due to its absence in the source populations. However, we detected a linkage pattern between Wolbachia and specific haplotypes which are prevalent in New South Wales, Queensland and South Australia, with the lowest haplotype diversity in New South Wales. This indicates that Wolbachia may have been acquired in the native range more recently than Cardinium, and Wolbachiamay have caused a selective sweep of a mitochondrial haplotype due to the maternal coinheritance. This could have confounded the identity of source populations in Australia, and, therefore, population genomic analyses will be required to investigate this further.