Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Simmons, Rabern [1], You, Li [2], Bateman, Craig [2], Short, Dylan [3], Kasson, Matt [3], Hulcr, Jiri [2].

New fungus-insect symbiosis: molecular and histological methods determine hyphal Polyporales symbionts of Ambrosiodmus ambrosia beetles.

Exotic ambrosia beetle-fungi symbioses are an emerging threat to trees and forests in North America. Beetles of tribe Xyleborini carry fungal symbiont inocula in specialized structures, known as mycangia, derived from several locations over their bodies. All Xyleborini studied to date are associated with several ascomycete mutualists. Ambrosia beetles in the genus Ambrosiodmus have been poorly examined for fungal symbionts and are related to a mycocleptic, or fungal-stealing, genus, suggesting the possibility that some Ambrosiodmus species may be devoid of symbionts. Ambrosiodmus lecontei, which is native to southeastern United States, and A. minor, which has been introduced from southern Asia, are common representatives of this genus in Florida. We collected individuals of A. lecontei and A. minor and isolated fungal cultures from both species using serial-dilution methods for isolating mycangial fungi. Using LSU and ITS rDNA sequences derived from these cultures, we determined these fungi to be members of the phlebioid clade of the Polyporales. Consequentially, to determine if these fungi are carried in mycangia instead of being surface contaminants, we sectioned heads of A. lecontei to determine the presence and location of mycangia in this species. We compared morphology of our isolates to fungi present in A. lecontei mycangia and noted the similarities. Uniquely in the ambrosia symbiosis, Ambrosiodmus mycangia contain fungal hyphal fragments rather than pseudo-mycelial growth. We conclude that Ambrosiodmus has a unique fungal symbiosis, the only such association known with a basidiomycete among ambrosia beetles. These results suggest that the several thousand ambrosia beetles that have never been examined for fungi may contain unknown and unexpected mycological diversity.

1 - University of Florida, School of Forest Resources and Conservation, PO Box 110410, Gainesville, FL, 32611, United States
2 - University of Florida, School of Forest Resources and Conservation, PO Box 110410, Gainesville, FL, 32611, USA
3 - West Virginia University, Division of Plant & Soil Sciences, PO Box 6108, Morgantown, WV, 26506, USA

Keywords:
none specified

Presentation Type: Oral Paper:Papers for Topics
Session: 36
Location: Salon 5/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 8:00 AM
Number: 36001
Abstract ID:132
Candidate for Awards:None