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Current Research
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Theoretical study of the effects on parasitoid-host dynamics
of reproduction by parasitized hosts.
When parasitoids attack the adult stage of their host, and
do not sterilize these hosts, host reproduction can occur
despite the parasitism. This in effect partially decouples
host mortality from parasitoid reproduction. I am exploring
the dynamical effects of this through analysis of stage-structured
delay-differential models.
This theoretical study is based loosely on a completed empirical
study of the effects of parasitism of the Southern green stink
bug (Nezara viridula) by the tachinid parasitoid Trichopoda
pilipes.
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adult southern green stinkbug with eggs of
the parasitoid T. pilipes
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Theoretical study of host-parasitoid and predator-prey metapopulation
dynamics.
I am using simulation models to explore several questions
concerning the dynamics of host-parasitoid interactions in
metapopulations. The most interesting of these questions is
the basic one of how metapopulation processes give rise to
density-dependent regulation of the metapopulation abundances.
Other questions involve the effects of more realistic spatial
structures than considered in previous models of this type,
and of non-random dispersal.
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example of dynamics of a persistent parasitoid-host
metapopulation model
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Pollination webs in Hawai`i.
Tad Fukami (Zoology Department), Don Drake (Botany Department)
and I are beginning a study of pollination webs — the network
of interactions among plants and pollinators — in several ecological
communities in Hawai`i. A major goal is to develop informational
resources — particularly, tools for identification of insect
pollinators, and pollen — to facilitate future research on
pollination in Hawai`i, and to develop a common protocol for such
studies.
Somewhat coincidentally, my graduate student Pat
Aldrich's dissertation research is on the pollination system
in Hawai`i's dry forests.
Methodological studies on topics in ecological and general statistics.
My role as statistical consultant for graduate students and faculty
in the biological sciences sometimes confronts me with questions
about study design or statistical methodology which require study.
At present I am engaged in two such projects, simulation studies
concerning
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the design of mark-recapture studies of very rare animals (in
collaboration with Paula Capece of the Botany Department), and
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rank-based alternatives to multifactor ANOVA.
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