Ophiostoma acarorum R.Chang & Z.W.de Beer

Chang, Runlei, Duong, Tuan A., Taerum, Stephen J., Wingfield, Michael J., Zhou, Xudong & Beer, Z. Wilhelm de, 2017, Ophiostomatoid fungi associated with conifer-infesting beetles and their phoretic mites in Yunnan, China, MycoKeys 28, pp. 19-64 : 29

Ophiostoma acarorum R.Chang & Z.W.de Beer sp. nov. Fig. 7

Etymology.

The epithet acarorum refers to the subclass Acari in the Arachnida to which all mite species belong from which 25 of the 29 isolates of this species were isolated.

Description.

Sexual state not observed. Hyalorhinocladiella-like asexual state: conidiophores (7-) 18-76.5 (-140) μm long; cells arising directly from the hyphae, (10.5-) 13.5-24.5 (-31) × (1-) 1.5-2 (-2) μm; conidia hyaline, smooth, oblong, (3-) 3.5-5 (-6.5) × (0.7-) 1-1.5 (-2.5) μm.

Culture characteristics.

Colonies hyaline at the beginning, becoming white to dark brown with age. Mycelium superficial on the 3% OA. Colony margin smooth. Colonies on 2% MEA flat, reaching 69 mm diam in 13 d at 30 °C. No growth observed at 5 °C. Optimal temperature for growth 25 °C.

Type material.

CHINA, Yunnan Province, Puer City, from Insectolaelaps sp. 1 in Orthotomicus angulatus gallery on Pinus kesiya bark, 17 Sep. 2010, S.J.Taerum, herbarium specimen of dried culture, PREM 61539 (holotype), CMW41850 = CBS139748 (ex-holotype culture).

Additional specimens examined.

CHINA, Yunnan Province, Puer City, from Histiostoma cf. sapromyzarum in Cyrtogenius luteus gallery on Pinus kesiya bark, 16 Sep. 2010, S.J.Taerum, PREM 61540, CMW41812 = CBS139658; from Histiostoma cf. sapromyzarum in Cyrtogenius luteus gallery on Pinus kesiya bark, 16 Sep. 2010, S.J.Taerum, CMW41798 = CBS139643.

Host.

Pinus kesiya .

Beetle vectors.

Ips acuminatus , Polygraphus szemaoensis .

Mite vectors.

Histiostoma cf. sapromyzarum (phoretic on Cyrtogenius luteus ), Insectolaelaps sp. 1 (phoretic on Ips acuminatus and Orthotomicus angulatus ).

Distribution.

At present known only from Yunnan, China.

Notes.

The hyalorhinocladiella-like asexual state of O. acarorum resembles that of O. pallidulum ( Linnakoski et al. 2010), one of its two closest relatives based on phylogeny (Fig. 3). Ophiostoma saponiodorum , the other close relative has a similar hyalorhinocladiella-like state, but can be distinguished based on the presence of a second, synnematous asexual state ( Linnakoski et al. 2010).