Assemblages of ophiostomatoid fungi vectored by Ips amitinus (Coleoptera: Scolytinae) on norway spruce depend on colonization time, position on the host tree and development stage

Abstract

SummaryThe small spruce bark beetle Ips amitinus is predominantly found in the spruce forests in mountainous areas of Central Europe. Its most important host trees are Norway spruce (Picea abies) and Scots pine (Pinus sylvestris). Under favourable weather and trophic conditions, this bark beetle can become dangerous, particularly for younger trees and plantations. The climate changes that we face today can be favourable to the species, which had not been economically important in the past but is currently causing forest damage. Information about the ecological/biological characteristics of I. amitinus in the literature is rare, especially for bark beetle-fungi associations; though bark beetle (Coleoptera: Scolytinae) species are known to be associated with variety of fungi. We investigated the factors affecting the associations of ophiostomatoid fungi with I. amitinus on Norway spruce. Material for this study was collected in the year 2010 near Dravograd, in north Slovenia, where Norway spruce trees were felled during the winter windthrow. Four hundred and forty-two samples (bark beetles and infested samples from wood discs, from two trees at 0.5 m, 6 m and 15 meters above the stump) were taken for ophiostomatoid fungi investigation. Isolation yielded a total of 625 isolates. Ophiostomatoid fungi were the most numerously represented group. Identified fungal isolates belonged to ten species. The most commonly found fungal associate was Ophiostoma brunneo-ciliatum, followed by Grosmannia penicillata, Ophiostoma bicolor, Ceratocystiopsis minuta, Grosmannia piceiperda, Endoconidiophora polonica, Ophiostoma piceae, Ophiostoma fuscum, Grosmannia cucullata, Graphium fimbriisporum. The association with O. fuscum, G. cucullata and G. fimbriisporum have not been demonstrated previously. The differences in distribution of fungi over different beetle life stages (adults, larvae, pupae) and infested wood were investigated.

Pathophysiology and transcriptomic analysis of Picea koraiensis inoculated by bark beetle-vectored fungus Ophiostoma bicolor

“…Ophiostoma bicolor is one of the dominant associate fungi with Ips spp. and Dendroctonus micans , which attacked various spruce species in Europe and north China ( Giordano et al, 2013 ; Nève Repe et al, 2018 ; Chang et al, 2019 , 2020 ; Chakraborty et al, 2020 ; Wang et al, 2020c , 2021 ). Previous studies have confirmed that the pioneer species in the associated fungal community of Ips , like Endoconidiophora spp., showed strong virulence, which could cause severe host necrosis and induce a drastic resistance response of host conifers.…”

Table_3.XLS

“…Ophiostoma bicolor is one of the dominant associate fungi with Ips spp. and Dendroctonus micans, which attacked various spruce species in Europe and north China (Giordano et al, 2013;Nève Repe et al, 2018;Chang et al, 2019Chang et al, , 2020Chakraborty et al, 2020;Wang et al, 2020cWang et al, , 2021. Previous studies have confirmed that the pioneer species in the associated fungal community of Ips, like Endoconidiophora spp., showed strong virulence, which could cause severe host necrosis and induce a drastic resistance response of host conifers.…”

Table_1.XLS

“…Ophiostoma bicolor is one of the dominant associate fungi with Ips spp. and Dendroctonus micans, which attacked various spruce species in Europe and north China (Giordano et al, 2013;Nève Repe et al, 2018;Chang et al, 2019Chang et al, , 2020Chakraborty et al, 2020;Wang et al, 2020cWang et al, , 2021. Previous studies have confirmed that the pioneer species in the associated fungal community of Ips, like Endoconidiophora spp., showed strong virulence, which could cause severe host necrosis and induce a drastic resistance response of host conifers.…”