Fungal community of necrotic and healthy galls in chestnut trees colonized by Dryocosmus kuriphilus (Hymenoptera, Cynipidae)

Abstract

Dryocosmus kuriphilus is a non-native pest that has recently spread through Europe with a special incidence along the Mediterranean Basin. The presence of this exotic wasp (originally from Asia) threatens stands and orchards of sweet chestnut (Castanea sativa Mill.) as it reduces tree growth and consequently fruit production. In this study the living mycobiota in leaves, healthy and necrotic galls collected from two sites in Cantabria (Northern Spain) was investigated. A total of twenty-two fungal taxa based on morphological and molecular traits were determined. In addition, we calculated fungal diversity and identified the dominant taxa among members of the mycobiota. Seven log-linear models were used to analyse whether fungal abundance varied between sites, types of plant material or fungal taxa. Our findings highlight the complex interactions between plant hosts, insect and the endophytic community, and are of potential interest in relation to the biological control of this important pest.