PROCEEDINGS: Index of Abstracts
EFFECTS OF ELEVATED CO2 AND SHADE ON THE DECOMPOSITION
OF SENESCED TREE FOLIAGE: IMPACTS ON THE GROWTH AND SURVIVAL OF
1-Department of Entomology, Michigan State University,
East Lansing, MI 48824. 2-Dow Gardens, Midland, MI 48640. 3-W. K.
Kellogg Biological Station, Hickory Corners, MI 49060. 4-School
of Forestry and Lake Superior Ecosystems Research Center, Michigan
Technological University, Houghton, MI 49931. 5-USDA Forest Service,
North Central Forest Experiment Station, East Lansing, MI 48824.
We tested the hypothesis that growth, survival, and reproductive
capacity of treehole mosquitoes can be affected by alterations of
forest sunlight and CO2 levels. Larval Aedes triseriatus
were fed naturally senesced, abscised foliage from red oak (Quercus
rubra) and paper birch (Betula papyrifera) seedlings grown in ambient
and elevated CO2 atmospheres. Oak seedlings were grown
in full sunlight. Birch were grown in full sun and partial shade.
Females fed birch leaves grown in elevated CO2 were larger
than those fed birch grown in ambient CO2. However, fewer
females emerged from microcosms containing birch foliage grown in
elevated CO2, which significantly lowered estimates of
microcosm total egg production. Elevated CO2 did not
affect the performance of mosquitoes reared on leaves of either
species grown in full sunlight. Shading birch foliage led to the
production of more mosquitoes of both sexes. Males fed shaded foliage
were larger and survivorship was higher for males and females, which
led to a significantly higher estimate of microcosm egg potential.
Birch diets produced larger females and a larger quantity of smaller
males than did diets of oak. Mosquitoes of both sexes took significantly
longer to develop on birch. Our results indicate that A. triseriatus
larvae are more sensitive to forest light intensity and tree species
composition than they would be to a doubling of atmospheric CO2