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Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Anthracnose of litchi fruits was characterized by internal and external brown circular lesions with well-defined margins on the pericarp, but not on the aril or seed. Colletotrichum sp., Pestalotiopsis sp., Fusarium sp., and Lasiodiplodia sp. were isolated from symptomatic fruit pericarp samples of cultivars Mauritius and Brewster in 2008-2010 cycles. Colletotrichum sp. (51%) and Pestalotiopsis sp. (17%) were isolated more frequently from symptomatic fruit pericarp samples of cultivar Mauritius in 2009. Colletotrichum sp. was isolated on PDA (39%) and in semi-selective medium (59%) from symptomatic Mauritius fruit pericarp samples in 2010, and from asymptomatic pericarp Brewster samples in 2009 (32%) and 2010 (21%) on PDA and 10% in semiselective medium; however it was not isolated from asymptomatic Mauritius pericarp in neither of the two harvesting years. Only Colletotrichum sp., reproduced the disease in the laboratory (17 out of 20 inoculated fruits) and in the field (19 out of 20 inoculated fruits). The fungus was morphologically and molecularly identified as Colletotrichum gloeosporioides Penz. [ABSTRACT FROM AUTHOR]

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring pest that vectors Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the etiologic agent of laurel wilt. To date, all confirmed U.S. hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. However, in previous research, an unknown variety of lychee, Litchi chinensis Sonn. (Sapindales: Sapindaceae), was found to be highly attractive to X. glabratus and elicited boring behaviors. Therefore, a study was undertaken to evaluate two commercial cultivars of lychee, 'Brewster' and 'Mauritius', for susceptibility to attack by X. glabratus, for transmission of R. lauricola, and for development of laurel wilt disease. In no-choice laboratory bioassays, 35 and 44% of females bored into cut bolts of 'Mauritius' and 'Brewster', respectively. Similar boring was observed on the trunks of two live 'Brewster' trees; but after 3 mo, there was no evidence of beetle reproduction, no symptoms of laurel wilt, and no recovery of R. lauricola from tissue associated with beetle galleries. Lychee trees artificially inoculated with an isolate of R. lauricola (RL4) that kills lauraceous hosts of this pathogen were asymptomatic after 1 mo, and assays for R. lauricola were negative. Chemical analysis indicated that lychee emits several sesquiterpene constituents in common with the Lauraceae, but at lower levels. Based on these data, we conclude that L. chinensis, although attractive to female X. glabratus, is not a likely reproductive host. This may be due to the inability of lychee wood to support growth of R. lauricola, the presumed primary nutritional symbiont of X. glabratus. [ABSTRACT FROM AUTHOR]