Abstract
Isolations from the granulate ambrosia beetle,
Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae: Xyleborini), collected in Georgia, South Carolina, Missouri and Ohio, yielded an undescribed species of
Ambrosiella in thousands of colony-forming units (CFU) per individual female. Partial sequences of ITS and 28S rDNA regions distinguished this species from other
Ambrosiella spp., which are asexual symbionts of ambrosia beetles and closely related to
Ceratocystis spp.
Ambrosiella roeperi sp. nov. produces sporodochia of branching conidiophores with disarticulating swollen cells, and the branches are terminated by thick-walled aleurioconidia, similar to the conidiophores and aleurioconidia of A.
xylebori, which is the mycangial symbiont of a related ambrosia beetle, X.
compactus. Microscopic examinations found homogeneous masses of arthrospore-like cells growing in the mycangium of X.
crassiusculus, without evidence of other microbial growth. Using fungal-specific primers, only the ITS rDNA region of A.
roeperi was amplified and sequenced from DNA extractions of mycangial contents, suggesting that it is the primary or only mycangial symbiont of this beetle in USA.
Keywords
Ambrosiella hartigii,
Anisandrus dispar,
Cnestus mutilatus,
Trypodendron,
Xyleborini,
Xylosandrus amputatus,
X. germanus
Citation
Harrington, Thomas C.; McNew, Douglas; Mayers, Chase; Fraedrich, Stephen W.; Reed, Sharon E. 2014. Ambrosiella roeperi sp. nov. is the mycangial symbiont of the granulate ambrosia beetle, Xylosandrus crassiusculus. Mycologia 106(4): 835-845.11 p.