A new Leptographium species associated with Tomicus piniperda in south-western China

Abstract

Tomicus species (Coleoptera: Scolytidae) are serious pests of pines with a wide distribution in Europe, Asia and America. In Yunnan, south-western China, T. piniperda has destroyed more than 0.5 million ha of Pinus yunnanensis in the past 15 years. A blue stain fungus belonging to the genus Leptographium is associated with both the shoot-feeding and trunk-attacking stages of the beetle's life cycle. The fungus is morphologically similar to the anamorph of Ophiostoma crassivaginatum and to L. pyrinum, which are both characterised by short robust conidiophores and hyphae covered by a granular layer. Both these species have been isolated from conifers and are associated with insects. After comparing the fungus from T. piniperda with similar Leptographium species, using light and scanning electron microscopy, we concluded that it represents a new taxon, which is described here as L. yunnanense sp. nov.

Two species of Leptographium isolated from blue-stained sapwood of Pinus khasya and bark beetles in Thailand

“…The fungus is not able to grow at 35°C. These characteristics also agree with the description of L. yunnanense by Zhou et al (2000).…”

“…6). Morphological characteristics of this fungus collected from Thailand agree with the description of L. yunnanense by Zhou et al (2000), except that the conidiogenous cells of this fungus [(20.0-)28.0-56.0(-60.0) µm] are longer than the description [(18.0-)23.0-26.0(-32.0) µm]. Optimum growth temperature of L. yunnanense is near 25°C.…”

“…Leptographium yunnanense was fi rst reported by Zhou et al (2000) from Pinus yunnanensis Franchet in Yunnan, South-western China. Later, Masuya et al (2002) reported the fungus was isolated from Pinus densifl ora in Japan.…”

Fungi associated withTomicus piniperdain Poland and assessment of their virulence using Scots pine seedlings

“…A similar spectrum of ophiostomatoid fungi has been found associated with T. piniperda in other parts of its distribution range in Europe [6,32,39,40,46,48,50,51]. Recently, some researchers have recorded that the mycobiota of T. piniperda in Asia differ from the European ones [14,17,[25][26][27][28][29][30][31][32][33][34][35][36][37][38]58]. The one record of blue-stain fungi associated with T. piniperda was made by Siemaszko in Poland, who found O. minus, O. piceae and O. piliferum [50].…”

Barcoding and microcoding using “identiprimers” withLeptographiumspecies

“…Leptographium species are difficult to identify based on morphological characters because the morphology is so similar among species. It is possible to identify Leptographium species accurately by employing molecular techniques; this is achieved through constructing phylogenies from available sequence data , Zhou et al 2000. Molecular characters are combined with morphological characters to describe new species ( Jacobs et al , 2001.…”