Ophiostoma species associated with bark beetles infesting three Abies species in Nikko, Japan

Abstract

Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied.

Three new Ophiostoma species with Pesotum anamorphs associated with bark beetles infesting Abies species in Nikko, Japan

“…infested with bark beetles in Nikko, Tochigi Pref., Central Honshu, Japan. Abies mariesii and A. veitchii trees were obtained from subalpine coniferous forests more than 2100 m above sea level; A. homolepis was obtained from a montane forest at about 1450 m. These isolates were obtained during the isolation study reported by Yamaoka et al (2004).…”

“…V by Yamaoka et al (2004) was isolated at a relatively high frequency from D. striatus infesting A. homolepis (Yamaoka et al 2004). However, it was not determined whether D. striatus is the major associate of the fungus because the number of beetles used for isolation studies was small (Yamaoka et al 2004). Yamaoka & Masuya,20 Perithecia superficialia in medio agari vel in cortice posita in superficie medii; pars basilaris atra, globosa vel subglobosa, 117-175 µm diametro, appendicibus brevibus fuscis hyphoides usque 97 µm longis ornata; colla atra, recta vel curvata, 330-617 µm longa, ad basim 39-58 µm lata, ad apicem (16-) 20-39 µm lata; hyphae ostiolares absentes.…”

“…S by Yamaoka et al (2004) was isolated at a relatively high frequency from D. striatus infesting A. homolepis (Yamaoka et al 2004). It has not yet been determined whether D. striatus is the major associate of the fungus because the number of beetles used for isolation studies was small (Yamaoka et al 2004). Aoshima (1965) investigated blue-stain fungi associated with P. proximus attacking A. sachalinensis (Fr.…”

“…In 2000 and 2001, we examined Ophiostoma species associated with bark beetles infesting Abies species in subalpine and montane forests in Nikko, Central Honshu, Japan. During the survey, many undescribed Ophiostoma species were found among the isolates (Yamaoka et al 2004). In the present articles, we describe three Ophiostoma species with Pesotum J.L.…”

“…are commonly associated with bark beetles that infest conifer trees (FranckeGrosmann 1963;Whitney 1982;Harrington 1993). Some isolation studies have been conducted on Ophiostoma species associated with bark beetles in Japan, but a few studies have been done on the fungi associated with bark beetles infesting Abies species in Japan (Aoshima 1965;Ohtaka et al 2002a,b;Yamaoka et al 2004). In 2000 and 2001, we examined Ophiostoma species associated with bark beetles infesting Abies species in subalpine and montane forests in Nikko, Central Honshu, Japan.…”