TABLE CONTENTS

SESSION THREE – MUTUALISTIC/PHORETIC ASSOCIATIONS AND
INVERTEBRATE PARASITIC NEMATODES
CONVENORS: ROBIN GIBLIN-DAVIS & KERRIE DAVIES
Entomophilic Nematodes for Predictions of Worldwide Nematode Species
Diversity
Giblin-Davis, R.M. (1), N. Kanzaki (1,2) & K.A. Davies (3)
(1) Fort Lauderdale Research & Education Center, University of Florida/IFAS, 3205 College Avenue, Davie,
FL 33314 USA; (2) Forest Pathology Laboratory, Forestry and Forest Products Research Institute, 1
Matsunosato, Tsukuba 305-0035 Japan; (3) Australian Centre for Evolutionary Biology & Biodiversity, The
University of Adelaide, Adelaide, South Australia 5005, Australia
The phylum Nematoda is the poorest known of the major metazoan phyla with about 25,000
nominal species. Based upon current dogma, most nematode diversity is represented by
species that are free-living in soil, marine, or freshwater ecosystems with a comparatively
small fraction hypothesized to be parasites of animals or plants. However, when insects are
seriously considered as hosts with the potential for spatial and temporal allopatry and
resulting cladogenesis, there could be a large proportion of nematode species involved in
highly specialized relationships with insects and other invertebrates. We use a clade-specific
approach for identifying lucrative radiations of unidentified nematode species. Firstly, we
associate suitable environmental factors (i.e., moisture, temperature and food availability)
with an invertebrate lineage to see if nematode prospecting makes sense. Invertebrates in
certain terrestrial environments may be less likely to have nematode associates than others
because all of their life history occurs outside the physiological range of potential nematode
associates. Secondly, we check for invertebrate lineages that have previously been reported
with seemingly unique or host-specific nematode genera. Thirdly, we work with invertebrate
groups that are easy to find in abundance and for which expertise is available for
identification. The correct identification of hosts and proper vouchering is critical to
reproducibility and understanding issues of host-specificity. This step can be accomplished
by sequencing the invertebrate host when experts are not available. Finally, we rear out or
collect invertebrates for dissections and are prepared to culture or sequence dauers or other
nematode stages that may be recovered. We have recently tried this approach with termites
for focal sampling of invertebrate-associated nematode diversity from the rainforests of
Central America and temperate regions of North America. We have also tried it with woodboring
insects from temperate forests in Japan, and figs, bees, and weevils from around the
world. We report on some of our unusual discoveries and discuss prospects for a better
estimate and understanding of patterns of entomophilic nematode biodiversity.
5 th International Congress of Nematology, 2008 8