First report of the ambrosia beetle Xylosandrus compactus and associated fungi in the Mediterranean maquis in Italy, and new host–pest associations

Abstract

In September 2016, a survey conducted in the Circeo National Park revealed an outbreak and serious damage caused by the black twig borer (Xylosandrus compactus) and its associated fungi in the Mediterranean maquis. Among the affected hosts, Quercus ilex, Viburnum tinus, Ruscus aculeatus, Pistacia lentiscus, Laurus nobilis and Ceratonia siliqua, showed flagging and wilting of branches and, in younger individuals, the death of the whole plant occurred. In total, 18 different fungal taxa were found associated with the insect. These included Ambrosiella xylebori, Geosmithia pallida, Fusarium spp., Epicoccum nigrum and Bionectria sp. This is the first report in Europe of X. compactus and associated ambrosia fungi in a natural environment.