Ooctonus vulgatus (Hymenoptera, Mymaridae), a potential biocontrol agent to reduce populations of Philaenus spumarius (Hemiptera, Aphrophoridae) the main vector of Xylella fastidiosa in Europe
- Published
- Accepted
- Subject Areas
- Agricultural Science, Biodiversity, Entomology, Spatial and Geographic Information Science
- Keywords
- biocontrol, Europe, Xylella fastidiosa, insect vector, oophagous, meadow spittlebug, parasitoid
- Copyright
- © 2019 Mesmin et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2019. Ooctonus vulgatus (Hymenoptera, Mymaridae), a potential biocontrol agent to reduce populations of Philaenus spumarius (Hemiptera, Aphrophoridae) the main vector of Xylella fastidiosa in Europe. PeerJ Preprints 7:e27941v1 https://doi.org/10.7287/peerj.preprints.27941v1
Abstract
As vector of Xylella fastidiosa (Wells, 1987) in Europe, the meadow spittlebug, Philaenus spumarius (Linnaeus, 1758) (Hemiptera: Aphrophoridae) is a species of major concern. Therefore, tools and agents to control this ubiquitous insect that develops and feeds on hundreds of plant species are wanted. We conducted a field survey of P. spumarius eggs in Corsica and provide a first report of Ooctonus vulgatus Haliday, 1833 (Hymenoptera, Mymaridae) as a potential biocontrol agent of P. spumarius in Europe. To allow species identification, we summarized the main characters distinguishing O. vulgatus from other European species of Ooctonus and generated COI DNA barcodes. We also assessed parasitism rates in several sampling sites, highlighting the top-down impact of O. vulgatus on populations of P. spumarius. Based on the geographic occurrences of O. vulgatus mined in the literature, we calibrated an ecological niche model to assess its potential distribution in the Holarctic. Our results showed that O. vulgatus potential distribution overlaps that of P. spumarius. Hence, O. vulgatus appears to be a promising biocontrol agent of the meadow spittlebug in Europe and it seems advisable to conduct research on this small parasitoid wasp to assess whether it could contribute to reduce the spread and impact of X. fastidiosa in Europe.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Illustration of the hatching experiment to quantify parasitism rates in four sampling sites
After inspection of the back of each leaf of C. monspeliensis collected in the Corsican maquis, parts of leaf containing whitish clusters were cut and put on moistened filter paper in Petri dishes (A). Panel B shows a zoom on the leaf, the white arrow pointing to the P. spumarius egg cluster. Leaf cuttings were observed under a binocular microscope to confirm the presence of P. spumarius eggs. Panels C, D and E show several groups of P. spumarius eggs. The orange pigmented spots and the black shields that can both be seen especially in panels C and D are respectively the future eyes of the larva and the characteristic “egg burster” used by the larva to break the egg shell (Weaver and King 1954). Panel E shows an egg cluster embedded in the frothy cement described by Weaver and King (1954). In panel D, the egg on the right has already hatched whereas the egg on the left hasn’t. Finally, panel F shows a first instar larva of P. spumarius in dorsal view while panel G show a male of O. vulgatus in ventral view
Supplementary methods
This appendix provides details regarding the species distribution modelling framework used in the study
Maximum likelihood phylogenetic tree including the newly generated sequences and all COI barcodes available in BOLD for Ooctonus species (last access July 12,2019)
Bootstrap (100 replicates) at nodes. The newly generated sequences are in red. The only four sequences identified as O. vulgatus in BOLD are in blue.