| |
Communication at the NABS Annual meeting, Keystone, 2000
(376) LIFECYCLE AND STANDING STOCK BIOMASS OF TORRENTICOLOUS INSECTS IN A MAUI, HAWAII STREAM.
M.D. McIntosh1, M.E. Benbow2, A.J. Burky2, and C.M. Way3. 1School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47401, 2Department of Biology, University of Dayton, Dayton, OH 45469-2320, 3Barry Vittor and Associates, Inc., 8060 Cottage Hill Rd., Mobile AL 36695
There are few stream bioenergetic studies from tropical island ecosystems. In Hawaiian streams, cascades and other torrential habitats are usually dominated by an epilithic midge, Telmatogeton torrenticola, and Procanace sp. (Canacidae) community. In this study, the lifecycle and standing stock biomass (SSB, as AFDM) of these species were determined from biweekly samples during a summer of normal and significantly lower stream discharge (1994 and 1995, respectively). Both torrential insects displayed multivoltine lifecycles with continuous reproduction. The combined midge and Procanace sp. SSB for 1994 and 1995 was 3195 and 1607 mg/m2, respectively, with T. torrenticola making up >95% in both years due to significantly greater individual AFDM and density. The SSB of T. torrenticola and Procanace sp. decreased (3176 to 1550 mg/m2) and increased (18.6 to 56.9 mg/m2 ) from 1994 to 1995, respectively, paralleling both density and individual AFDM changes for each taxa between years. Observations indicated a change in the epilithic community from a dominate adanate biofilm layer in 1994 to filamentous green algae in 1995. We hypothesize that this change in habitat architecture altered the flow dynamics and food resources in a manner that had opposing effects on each insect population and corresponding interspecific interactions.
Presented at 1:00 PM on Wednesday, May 31, 2000 in Life History Characteristics
|
|
