Some ecology of benthic insects in Gladfelter Pond.

Abstract

Benthic and emerging fauna were investigated at Gladfelter Pond from September, 1972, through September, 1973. Species diversity analyses were made on the benthic community by using the equation of Shannon Weaver (1949). Relationships between benthic fauna and emerging fauna were established. A total of 15,419 benthic organisms representing 33 taxa were collected. Eighty-two percent of the total individuals collected were represented by the phantom midge larva, Chaoborus punctipennis Say. Six percent were represented by the fingernail clam, Sphaerium sp. Hexagenia sp. composed 3 %of the total benthic fauna collected, although no adults were caught in the emergence traps. The majority of the benthic organisms collected was from the 3 m and 4 m depths, 34 %and 49 %respectively. A total of 775 emerged insects was collected. Seventy-four percent of all emerged insects collected belonged to the family Chironomidae. By comparison, only 26 %of the benthic fauna collected were Chironomidae. There were no significant differences among the numbers of individuals caught in the three traps. The two major families emerging, Culicidae and Chironomidae, had peak emergence periods only two weeks apart. There were no significant differences found in annual diversity (d) by depth, but there were significant differences in monthly diversity when all depths were combined.