Nidularia pulvinata (Planchon) (Hemiptera: Kermesidae) urban outbreaks associated with entomopathogenic fungi

Abstract

Pest outbreaks often give to insect pathogens the opportunity to infect their host species eventually leading them to death. Recent Nidularia outbreaks off urban Quercus ilex L. showed some cases of entomopathogenic fungi virulence, apparently sustained by species of Fusarium and other fungi. Infection is apparent on the Nidularia population because fungi provoke the scale color shifting to orange or dull-green in medium in large patches. After the isolation in an axenic culture of the Kermesid-associate Mycota, ITS genomic regions amplified by PCR using the universal ITS5/ITS4 primers were sequenced by external service (Macrogen, Seoul, South Korea) for molecular identification. Blast analysis (http://blast. ncbi. nlm. nih. gov/Blast. cgi) of the ITS sequence showed a high homology with Quambalaria cyanescens (de Hoog & G. A. de Vries) Z. W. de Beer, Begerow & R. Bauer 2006 (Fungi: Basidiomycota), (identity: 97-96%; e-value 0. 0; coverage 82-75%), Fusarium acuminatum Ellis & Everh. 1895 (Fungi: Ascomycota) and Fusarium avenaceum (Fr. ) Sacc. 1886 (Fungi: Ascomycota) (identity: 99%; e-value 0. 0; coverage 82-80%), and Penicillium sumatraense Svilv. 1936 (Fungi: Ascomycota) (identity: 100%; e-value . 0; coverage 95-91%). We investigate the biological and ecological role of the above-recorded fungi by correlating the age of infected scale and their age. Mass culturing of the most promising pathogen will lead to semi-field trials to demonstrate the isolate entomopathogenic ability.

Finally, we discuss the case of homonymy between the fungal Taxon named Nidularia pulvinata (Schwein.) (Gasteromycetes) and the scale Nidularia pulvinata (Planchon) that can lead to some confusion.