ARS | Publication request: NEMATODE AND MITE ASSOCIATES OF BARK BEETLES ON PINE IN LOUISIANA (USA) AND ON ELM IN AUSTRIA

Submitted to: Society of Nematology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2004
Publication Date: September 15, 2004
Citation: Carta, L.K., Erbe, E.F., Ochoa, R., Klepzig, K., Moser, J.C., Konrad, H., Kirisits, T. 2004. Nematode and mite associates of bark beetles on pine in Louisiana (USA) and on elm in Austria. J. Nematology 36: 310.

Technical Abstract: Numerous adult male and female nematodes were found associated with two mites in galleries of the small southern pine engraver Ips avulsus on loblolly pine (Pinus taeda) in Louisiana. These nematodes were identified as Parasitorhabditis subelongati, with minor morphological differences from the original description. One of the phoretic mites, Elattoma benneti, resided under and around the beetle legs. The other mite, Iponemus truncatus eurus, resided on the beetle thorax and appeared to puncture a nematode as seen when cryo-fixed under a scanning electron microscope. Until now, P. subelongati was reported in Russia on Ips subelongatus, and in the United States on Ips calligraphus ponderosae from northern New Mexico. We now report P. subelongati from a new host (I. avulsus) and a new location, the Southeastern United States. Additionally, on Austrian elms (Ulmus minor) nine phoretic mite species were associated with two elm bark beetles, Scolytus multistriatus and S. pygmaeus, which act as vectors of the Dutch elm disease fungus, Ophiostoma novo-ulmi. Under the elytra of both beetle species small female nematodes (285 - 350 micrometers) belonging to genus Cryptaphelenchus were observed. Larger (720 - 750 micrometers) adult Neoparasitylenchus sp. were present inside abdomens of S. multistriatus, but absent from S. pygmaeus. The beetle S. multistriatus, but not S. pygmaeus, has also been reported in the United States, Australia and New Zealand. The two nematodes appear to be new associates of the beetles. The specific identity of the nematodes and the trophic role of the mites are presently under investigation.