In 2009 the alien Palm borer Paysandisia archon (Lepidoptera, Castniidae) was first reported in Northern Italy (Veneto Region) on Trachycarpus fortunei. A survey was carried out during 2009-2011 to study the pest phenology and damage in the infested area. Infested palms were cut down to verify the infestation level. Several palms with severe decline symptoms had only a moderate mechanical damage by P. archon whereas expanding necrosis of leaf bases, starting from the larval galleries, occurred. Therefore, a study on the necrosis agents possibly linked to larval damage was carried out. Samples of leaf bases with larval galleries and necrosis were collected from infested palms. Mature and young leaf base samples were removed from both naturally and artificially infested palms. From each leaf, both necrotic and healthy tissue fragments were removed, incubated on Difco PDA agar and then the emerging fungal colonies were isolated. The most frequent fungus isolated from the necrotic tissues was Talaromyces cf. erythromellis. This species had higher occurrence on necrotic tissues rather than on healthy tissues. In a pathogenicity test by inoculation of leaf bases collected from healthy palms, T. cf. erythromellis demonstrated to be able to induce large necrotic areas. Fusarium proliferatum was also frequently isolated but it was not associated with the necrotic areas.
G. et al. (Sun,) studied this question.