TABLE CONTENTS

Metapopulation Biology of EntomopathogenicNnematodes
Parwinder, S., P. Grewal, G.B. Jagdale, A. Saeb, R.A.J. Taylor, C.W. Hoy & A. Michel
Department of Entomology, Ohio State University, OARDC, Wooster, OH 44691, USA
Metapopulation biology is concerned with the dynamic consequences of migration among
local populations and the conditions of regional persistence of species with unstable local
populations. Thus, a metapopulation is defined as a population of unstable local populations,
inhabiting discrete habitat patches. One of the hallmarks of metapopulations is the
appearance and disappearance of subpopulations from habitat patches as a result of frequent
extinction and recolonization. We found evidence of metapopulation dynamics in an
endemic population of H. bacteriophora in a vegetable production area in North Central
Ohio. A total of 143 sites were sampled once a month from June to August in 2005 and 2006
from six distinct habitats located at approximately 2-3 miles apart: vegetables (20 samples),
row crops (20), residential lawns (21), unmanaged crop ‘grassy borders’ (44), shrubs (18) and
forested wetlands (20). At each sampling time, each site was located with a Global
Positioning System (GPS) and 10 soil cores (2.5 cm diameter, 25cm depth) were randomly
collected from a 1m 2 area. Cores were combined to form a composite sample and stored at
5°C until EPNs were extracted using a modified insect baiting technique. We analyzed the
changes in nematode abundance for frequencies of extinction and recovery. Both temporal
and spatial pattern of extinction and recovery are apparent in these data, consistent with
metapopulation dynamics. We also investigated genetic variation in H. bacteriophora
collected from the above sites using the mitochondrial gene, cytrochrome oxidase subunit
(cox1). We calculated cox1 DNA sequence based pairwise distances between nematodes
from different sites using maximum composite likelihood substitution model and found
significant genetic variation. We also determined relationships between different cox1
haplotypes for the 22 nematode isolates. The spanning tree showed the differences among
haplotypes represented as number
5 th International Congress of Nematology, 2008 144