1 September 2009 Transport of Fungal Symbionts by Mountain Pine Beetles
K.P. Bleiker, S.E. Potter, C.R. Lauzon , D.L. Six
Author Affiliations +

The perpetuation of symbiotic associations between bark beetles (Coleoptera: Curculionidae: Scolytinae) and ophiostomatoid fungi requires the consistent transport of fungi by successive beetle generations to new host trees. We used scanning electron microscopy and culture methods to investigate fungal transport by the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins. MPB transports its two main fungal associates, Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield and Ophiostoma montium (Rumbold) von Arx, in sac-like mycangia on the maxillary cardines as well as on the exoskeleton. Although spores of both species of fungi were observed on MPB exoskeletons, often in pits, O. montium spores were generally more abundant than G. clavigera spores. However, a general scarcity of spores of either species on MPB exoskeletons compared with numbers on scolytines that lack sac-like mycangia indicates that fungal transport exteriorly on MPBs is incidental rather than adaptive. Conidia were the dominant spore type transported regardless of location or species; however, our results suggest that once acquired in mycangia, conidia may reproduce in a yeast-like form and even produce hypha-like strands and compact conidiophore-like structures. Fungi that propagate in mycangia may provide beetles with a continual source of inocula during the extended egg-laying period.

© 2009 Entomological Society of Canada
K.P. Bleiker, S.E. Potter, C.R. Lauzon , and D.L. Six "Transport of Fungal Symbionts by Mountain Pine Beetles," The Canadian Entomologist 141(5), 503-514, (1 September 2009). https://doi.org/10.4039/n09-034
Received: 12 March 2009; Accepted: 1 June 2009; Published: 1 September 2009

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top