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United States Department of Agriculture

Agricultural Research Service

Research Project: Alternatives to Methyl Bromide: Mitigation of the Threat from Exotic Tropical and Subtropical Insect Pests

Location: Subtropical Horticulture Research

Title: Geographic variation in the mycangial mycoflora of Xyleborus glabratus in Florida

Authors
item Campbell, Alina -
item Ploetz, Randy -
item Kendra, Paul
item Montgomery, Wayne

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 13, 2014
Publication Date: N/A

Technical Abstract: Laurel wilt kills Persea borbonia and other American members of the Lauraceae. It is caused by Raffaelea lauricola, a fungal symbiont of an exotic ambrosia beetle, Xyleborus glabratus. R. lauricola and other fungi were quantified in X. glabratrus collected from three locations in Florida. A Miami-Dade Co. (MDC) site, 25.8oN, was populated by P. palustris, a Highlands Co. (HC) site, 27.9oN, by P. borbonia, P. humulis and P. palustris, and an Alachua Co. (AC) site, 29.8oN, by P. borbonia. Mycangia from individual females were macerated and plated on CSMA and ½ PDA. Seven putative taxa were identified based on identical LSU genotypes and colony phenotypes. With the exception of R. lauricola and Zygozyma oligophaga, it was not possible to match LSU genotypes/sequences with those deposited in GenBank, as the remaining taxa were 98 to 99% similar to two or more species of Fragosphaeria, Leptographium, Grosmannia and/or Ophiostoma. The numbers of R. lauricola colony forming units (CFUs) in X. glabratrus varied by location (p<0.0003), as beetles from MDC had more CFUs (3,532) than those from HC (2,593) and AC (1,829). The numbers of fungal species also differed by location (p<.0001), as 80% of the individuals from AC and MDC carried =3 species, compared to 31% of those from HC. The results indicate that climate and vegetation may affect fungal diversity and the relative abundance of R. lauricola in the mycangia of X. glabratus.

Last Modified: 10/25/2014
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