Gall morpho-type corresponds to separate species of gall-inducing thrips (Thysanoptera: Phlaeothripidae)

Abstract

CSIRO Entomology, GPO Box 1700, Canberra ACT 2601, AustraliaReceived 13 December 2004; accepted for publication 5 December 2005Kladothrips rugosus Froggatt has previously been considered a single polyphagous species that, in Australia,induces galls on several species of Acacia, with the gall structure varying both within and between hosts. On Acaciapapyrocarpa, two types of gall are induced by this species, one with the surface ridged but the other with the surfacesmooth. Using sequence data from cytochrome oxidase subunit I (CO I) and elongation factor-1 alpha gene frag-ments, we show that the thrips inducing these two gall-types are genetically distinct and comprise separate lineages.Uncorrected ‘ p’ distances calculated from CO I gene fragments were 0.000 and 0.006 within lineages and 0.074 and0.078 between lineages. The between-lineage distances are comparable with distances between morphologically dis-tinct species of other Acacia gall-thrips. Re-examination of adult thrips from the two gall types revealed consistentdifferences in body colour, as well as in body sculpture. Together with observations on gall founding behaviour, thesedata indicate that the thrips populations in the two gall types on A. papyrocarpa are reproductively isolated andshould be considered as separate species. The form from smooth galls on A. papyrocarpa is therefore described asKladothrips nicolsoni sp. nov., although the form from ridged galls can be considered only as ‘K. rugosus agg.’.These inconsistencies in the taxonomic status of the various units within the K. rugosus species complex are dis-cussed, although most of them cannot be distinguished morphologically at present. © 2006 The Linnean Society ofLondon, Biological Journal of the Linnean Society, 2006, 88, 555–563.