Submission of mitochondrial sequences of two Botanophila species developing on yellow starthistle (Centaurea solstitialis L.) and diffuse knapweed (Centaurea diffusa Lam.) in northern Greece

Authors: BON, MARIE-CLAUDE - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); KASHEFI, JAVID - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); GUERMACHE, FATIHA - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); SMITH, LINCOLN

Submitted to: Genbank
Publication Type: Database / Dataset
Publication Acceptance Date: 1/30/2021
Publication Date: 1/30/2021
Citation: Bon, M., Kashefi, J., Guermache, F., Smith, L. 2021. Submission of mitochondrial sequences of two Botanophila species developing on yellow starthistle (Centaurea solstitialis L.) and diffuse knapweed (Centaurea diffusa Lam.) in northern Greece. Genbank. MW590595.1 to MW590603.1.

Interpretive Summary: Yellow starthistle (Centaurea solstitialis L.) and diffuse knapweed (Centaurea diffusa Lam.) of the Asteraceae family are two invasive plants that significantly modify or disrupt ecosystems in the western United States. Both plants native to a wide region of Eurasia have been targeted for classical biological control as there is a need to find a sustainable control strategy to protect ecosystems in the western United States. Recent attention has been given to northern Greece in the native range for discovery of new natural enemies to complement the existing biocontrol agents. Extensive field surveys resulted in the evidence of fly larvae feeding on the center of rosettes of both plants. DNA analysis sorted these fly larvae into two Botanophila species and suggested that one species is similar to Botanophila turcica Hennig, a possible biological control agent of another invasive plant, Carthamus lanatus L. (Asteraceae). This is the first time that Botanophila turcica is reported to occur in Greece on Yellow starthistle and diffuse knapweed. This finding extends the known host range of Botanophila turcica, and should be taken into account in future host range specificity testing of the fly regarded as a key step in a classical biological control program.

Technical Abstract: Two exotic plants of the Asteraceae family, Centaurea solstitialis L. (yellow starthistle) and Centaurea diffusa Lam. (diffuse knapweed), that significantly modify or disrupt ecosystems in the western United States, have been targeted for classical biological control based on the assumption that their abundance and spread are effectively limited by their natural enemies in the native range. During exploration for new natural enemies in northern Greece, one of the authors collected fly larvae feeding on the center of rosettes of diffuse knapweed at Kilkis near Thessaloniki in 2002 and more recently in 2018 in yellow starthistle at Galani near Kozani. Identifying fly larvae by morphology is extremely challenging, but nowadays the application of DNA barcoding can partly address this challenge. The analysis of the "DNA barcode”, a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene, in these larvae sorted sequences into two divergent barcode groups in both plants which might be considered as two hypothetical species based on the barcode gap strategy. The sequences were compared to reference Diptera barcodes made publicly available in online databases such as the Barcode of Life Data System (BOLD) and Genbank. Homology-search assigned unambiguously the two hypothetical species to the rank of the Botanophila genus (Diptera: Anthomyiidae) but not of the species. Complete sequences of the COI gene were generated from these two hypothetical species and deposited to Genbank. Subsequently, we sequenced the barcode of two adults of Botanophila turcica Hennig graciously lent to the authors by Janine Vitou from CSIRO and identified by the taxonomist, Verner Michelsen from the Natural History Museum of Denmark, that had been reared from Carthamus lanatus L. (Asteraceae) in France during studies to evaluate this fly as a possible biological control agent of this plant. Sequence comparison allowed us to identify one of the hypothetical species as Botanophila turcica. Here we report for the first time the occurrence of B. turcica in two Centaurea species in Greece. Our finding extends the known host range of this fly, which should be taken into account in future host range specificity testing of the fly. The other Botanophila species developing in the two Centaurea species remains unidentified to date.