Activity of natural occurring entomopathogenic fungi on nymphal and adult stages of Philaenus spumarius

Nicola Bodino; Riccardo Barbera; Natalia González-Mas; Stefano Demichelis; Domenico Bosco; Paola Dolci

doi:10.1016/j.jip.2024.108078

Activity of natural occurring entomopathogenic fungi on nymphal and adult stages of Philaenus spumarius

J Invertebr Pathol. 2024 Mar 2:204:108078. doi: 10.1016/j.jip.2024.108078. Online ahead of print.

Authors

Nicola Bodino¹, Riccardo Barbera², Natalia González-Mas³, Stefano Demichelis⁴, Domenico Bosco⁵, Paola Dolci⁶

Affiliations

¹ Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università Degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, TO, Italy; CNR-Istituto Per La Protezione Sostenibile Delle Piante, Strada Delle Cacce, 73, 10135 Torino, Italy. Electronic address: nicola.bodino@unito.it.
² Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università Degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, TO, Italy. Electronic address: riccardo.barbera@unito.it.
³ Department of Agronomy, María de Maeztu Excellence Unit DAUCO, ETSIAM, University of Cordoba, C4 Building, Celestino Mutis, Campus de Rabanales, 14071, Cordoba, Spain. Electronic address: nataliagmas@hotmail.com.
⁴ Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università Degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, TO, Italy. Electronic address: stefano.demichelis@unito.it.
⁵ Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università Degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, TO, Italy; CNR-Istituto Per La Protezione Sostenibile Delle Piante, Strada Delle Cacce, 73, 10135 Torino, Italy. Electronic address: domenico.bosco@unito.it.
⁶ Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università Degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, TO, Italy. Electronic address: paola.dolci@unito.it.

PMID: 38438078
DOI: 10.1016/j.jip.2024.108078

Abstract

The spittlebug Philaenus spumarius (Hemiptera: Aphrophoridae) is the predominant vector of Xylella fastidiosa (Xanthomonadales: Xanthomonadaceae) in Apulia, Italy and the rest of Europe. Current control strategies of the insect vector rely on mechanical management of nymphal stages and insecticide application against adult populations. Entomopathogenic fungi (EPF) are biological control agents naturally attacking spittlebugs and may effectively reduce population levels of host species. Different experimental trials in controlled conditions have been performed to i) identify naturally occurring EPF on P, spumarius in Northwestern Italy, and ii) evaluate the potential for biocontrol of the isolated strains on both nymphal and adult stages of the spittlebug. Four EPF species were isolated from dead P. spumarius collected in semi-field conditions: Beauveria bassiana, Conidiobolus coronatus, Fusarium equiseti and Lecanicillium aphanocladii. All the fungal isolates showed entomopathogenic potential against nymphal stages of P. spumarius (≈ 45 % mortality), except for F. equiseti, in preliminary trials. No induced mortality was observed on adult stage. Lecanicillium aphanocladii was the most promising fungus and its pathogenicity against spittlebug nymphs was further tested in different formulations (conidia vs blastospores) and with natural adjuvants. Blastospore formulation was the most effective in killing nymphal instars and reducing the emergence rate of P, spumarius adults, reaching mortality levels (90%) similar to those of the commercial product Naturalis®, while no or adverse effect of natural adjuvants was recorded. The encouraging results of this study pave way for testing EPF isolates against P, spumarius in field conditions and find new environmentally friendly control strategies against insect vectors of X. fastidiosa.

Keywords: Biological control agent; Blastospore; Insect pathogenic fungi; Integrated pest management; Lecanicillium aphanocladii; Xylella fastidiosa.