Abstract:

An Investigation of the Inhabitants and Prey of the Purple Pitcher Plant, Sarracenia Purpurea L., with particular Emphasis on Metriocnemus knabi Coq. (Diptera: Chironomidae). Latisha R. Parker; Dr. Richard M. Duffield, Department of Biology, Howard University, Washington, DC.

Fifty leaves of the carnivorous purple pitcher plant, Sarracenia purpurea L., collected from Big Run Bog, Tucker County, West Virginia, were dissected and analyzed for invertebrates. These inhabitants either make a home inside of the leaves or are prey that help sustain the plant. The predominate prey that were found within the leaves were ants, spiders, and springtails. Metriocnemus knabi, a species of fly, is able to live and complete its lifecycle within the leaves of the plant. Thirteen hundred and fifty-three chironomid larvae were recovered from the leaves. The number of larvae per plant ranged from a low of approximately six to a high of eighty-four. Clumping length measurement of the larvae in data increments of five units demonstrated the presence of two size classes that represented the third and fourth instar larvae. The fourth instar larval stage was found to be dominant. This data is also supported by the work done by C.G. Patterson and C.J. Cameron (1981). It is generally expected that the midge, Metriocnemus knabi, overwinters primarily as third and fourth instar larvae. This is important in determining how and why the larvae survival rates are greatly increased when the larva maintains dormancy during the winter months and subsequent development in the spring and summer. The data collected support this hypothesis.