First Report of Neozygitessp. (Entomophthoromycota: Neozygitales) Affecting the Woolly Poplar Aphid

The woolly poplar aphid, Phloeomyzus passerinii, causes severe damage to poplars in Southern Europe and Asia, where outbreaks of this pest can lead to massive mortality of trees in mature stands. In Chile, this aphid was reported for the first time in 1997 in plantations of Populus nigra. During April 2016 and again in March 2017 (autumn season), several mycosed individuals were found attached to the poplars’ twigs. The fungus was identified as a Neozygitesspecies by its characteristic morphology with subglobose primary conidia, 19.8 ± 0.4 × 16.1 ± 0.4 μm, with a small, flat papilla, produced on the surface of cadavers, and capilliconidia that are almond shaped but rarely observed, 21.7 ± 0.8 × 14.4 ± 0.6 μm. The resting spores were subglobose, 26.3 ± 0.5 × 21.2 ± 0.5 μm, black in mass, with a thick more or less smooth-surfaced wall, and formed inside the aphid. Neozygitescomprises a relatively homogeneous group of species exclusively pathogenic to arthropods. Their narrow host ranges make them potentially valuable biocontrol agents. This is the first report worldwide of any Neozygiteson P. passerinii.