Long-term survival of the wood-inhabiting nematode Bursaphelenchus ulmophilus in cultures of insect-dispersed and nematode-dispersed fungi

Summary Several fungi found on vector beetles and nematodes were found to be capable of maintaining a high population abundance of the pathogenic nematode Bursaphelenchus ulmophilus , associated with Dutch elm disease, at a temperature of 25°C without frequent re-cultivation and for a long period (6 months). The fungi used as substrates for the nematode cultivation were originally isolated from the natural vectors, beetles and nematodes, identified by ITS1/2 and 5.8S or elongation factor 1-alpha genes. Mucor hiemalis and Alternaria alternaria were the best substrates for maintaining nematode abundance. Species of the genera Trichoderma , Ophiostoma and the species Graphium radicatum were good substrates. Previously, Trichoderma spp. were characterised as potential biocontrol agents for Bursaphelenchus spp. in short-term experiments. The laboratory non-sporulating isolate of Botrytis cinerea , the fungi Sydowia polyspora and Leptographium piceardum do not support long-term propagation of B. ulmophilus . The results can be used for economical long-term storage of live nematode cultures of Bursaphelenchus spp. and species of the phylogenetically related Aphelenchoididae.