A new light in the diversity of the Aprostocetus egg parasitoids associated with the invasive viburnum leaf beetle, Pyrrhalta viburni, using an integrative approach

Authors: LAMBIN, NICOLAS - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); DESURMONT, GAYLORD - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); BON, MARIE-CLAUDE - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); KERDELLANT, ELVEN - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL); GUERMACHE, FATIHA - EUROPEAN BIOLOGICAL CONTROL LABORATORY (EBCL)

Submitted to: International Insects Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/5/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The viburnum leaf beetle, Pyrrhalta viburni (Paykull), is an invasive chrysomelid native to Eurasia and invasive in North America, where it was introduced in the 1920s in Canada, and is now considered a major landscape and forest pest in southern Canada and northeastern U.S. Both larvae and adults are dietary specialists restricted to plants in the genus Viburnum (Adoxacae, Dipsacales), a clade of small trees and shrubs of worldwide importance as ornamentals. In its introduced range, P. viburni is attacking populations of several native Viburnum spp. in natural habitats (e.g., forest understories, old-fields, and wetlands) and managed landscapes. Surveys in the context of a classical biological control program focusing on egg parasitoids including Aprostocetus started in 2018 in Europe. Overall the diversity of these Aprostocetus (Hymenoptera : Eulophidae) is poorly documented and in particular the taxonomic distinction between A. suevius and A. celtidis remains unresolved. With moderate effort, we sampled 33 Eurasian Aprostocetus populations and we started using DNA barcoding of mtCOI DNA to estimate the diversity of the region. Barcode gap analysis did not detect a gap suggesting a single species. Clustering analysis unraveled a significant genetic structuring across populations with marked geographic patterning of six genetic clusters. Subsequently measurements of the ovipositor length and nuclear gene analysis on these clusters were congruent with the barcoding gap analysis, and hence underlined the need for synonimizing these two taxa. Other integrative approaches including simple MALDI-TOF MS are currently under evaluation and further work is currently underway to assess the specificity of these genetic clusters of this Aprostocetus species on the elm leaf beetle, P. Luteola, a serious pest of ornamental elms in most areas where they are grown. The study is presented here by emphasizing the importance of building up integrative and simple approaches for studying the diversity of potential biocontrol agents when funding is limited.