First record of Ektaphelenchoides pini associated with Ips sexdentatus on Pinus nigra laricio in Italy

Abstract

In February 2015, an unexpected windstorm downed five hectares of a European black pine Pinus nigra subsp. laricio forest formation located close to Vallombrosa, Florence (Central Italy). In the following spring, an extensive survey was conducted in the area. Felled trees, stumps and all the suitable plant material were screened for the presence of the pinewood nematode (PWN), Bursaphelenchus xylophilus, by sampling wood and bark. Bark beetles were then collected from the gallery systems on the inner side of bark samples and observed in the laboratory. The following bark beetles were morphologically identified: Ips sexdentatus, Orthotomicus erosus, O. laricis and Pityogenes bidentatusa. The dissection of Ips sexdentatus allowed the extraction of numerous nematodes that were morphologically and molecularly identified as Ektaphelenchoides pini. Conversely, only few nematode specimens were isolated from either pine bark or wood. These individuals could be only molecularly identified and belonged to an undescribed nematode taxon. Even though no PWN was recorded in the investigated sites, our survey allowed the detection of a new association between E. pini and I. sexdentatus on P. nigra.

New alien and native Ektaphelenchid nematodes (Tylenchomorpha: Ektaphelenchinae) from China with details on host association and geographical distribution

“…), the beetles were inhabiting the Pinus sp. in Italy, the authors reported the 100% infestation rate since every insect was found infested by nematodes (d'Errico et al 2020).…”

“…Other species are E. attenuata (Massey 1974) Baujard 1984 E. spondylis Kanzaki, Giblin-Davies andCenter 2009 andE. pini (Massey 1966) Baujard 1984 these were found in the body cavity of Dendroctonus terebrans Olivier, Spondylis buprestoides L. and Ips sexdentatus Boerner respectively (Massey 1974;Kanzaki et al 2009;d'Errico et al 2020). The rest of the Ektaphelenchoides species were not reported in association with insect, these were either isolated from the bark samples having bark beetle galleries or from the rhizosphere of different woody perennials.…”